national security agency journal articles world war ii german ...

NATIONAL SECURITY AGENCY
JOURNAL ARTICLES
WORLD WAR II
GERMAN CRYPTOLOGY
BACM RESEARCH
HTTP://WWW.PAPERLESSARCHIVES.COM

CONTENTS
NATIONAL SECURITY AGENCY
JOURNAL ARTICLES
WORLD WAR II GERMAN CRYPTOLOGY
NSA Technical Journal Articles:
Cryptanalysis in The German Air Force - April 1959 - Vol. IV, No. 2
Cryptologic Quarterly Articles:
A World War II German Army Field Cipher and How We Broke It -
Winter 1995 - Vol. 14, No. 4
Cryptologic Spectrum Articles:
The German Cryptologic Effort 1918-1945 - Summer 1975
The German Comint Organization in World War II - Spring 1978 - Vol.
8, No. 2
German Intercept Successes Early in World War II - Fall 1978 - Vol.
8, No. 4
Critical Analysis of German Operational Intelligence Part II - Winter
1980 - Vol. 10, No. 1

NSA Technical Journal Article:
Cryptanalysis in The German Air Force
April 1959 - Vol. IV, No. 2

"'TOP 5EERH-
Cryptanalysis in the German Air Force
BY OBERLEUTNANT WALDEMAR WERTHER
?_bjJ aUlet
The r~port from which this article is taken was prepared after World
War II at the request of an Army Air Corps team interrogating former
Axis COMINT personnel. The extract is published here for its general
interest to readers of the Journa\.
I. A SHORT HISTORICAl. SURVEY OF THE DEVELOPMENT OF TilE F.ASTERN CRYPT­
ANALYSIS GROUP OF TilE GERMAN AIR FORCE
During the period of preparation for the establishment of the intercept
equipment of the Air Force in 1936, the first State employees intended
for cryptanalysis (who were all of them civilians up to the outbreak
of the war) were sent to the permanent intercept posts of the
Army in the East for the purpose of basic training. The results of
this training were unsatisfactory because the Army was reticent in releasing
even the most elementary information, and furthermore, because
the individuals sent lacked in most cases the necessary qualifications
for their work; the personnel officials made their selections on
anything but a proper basis, and appointed many persons who turned
out to be completely unsuitable for the work of a cryptanalyst. The
creation of a capable and successful cryptanalytic group was accomplished
only in the course of the following years of tiresome work,
without outside assistance, and through an internal development
achieved by dropping numerous unsatisfactory elements.
In the summer of 1937, four cryptanalysts were working on Soviet·
traffic at the Cryptanalytic Bureau of the Air Force (Chi-Stelle).
The other Eastern powers were either treated very superficially, largely
as a side issue by our Soviet section, or not processed at all. The
cryptanalytic groups of the outstations of the Air Force Intercept
Service (cover name: "Radio Weather Receiving Stations") also consisted
of a few poorly trained and often incompetent workers. A
worth-while organization for breaking new systems was developed only
at the cryptographic bureau. The outstations were barely able to
decode the encoded messages with the code in front of them.
At the outbreak of the war in 1939, the cryptanalytic groups both
in the central office and in the outstations had grown to about 10 men
each, and they were included in the newly established intercept companies.
.The training of the individual analyst was continuously improved
through conferences, short training courges, and exchange
groups. of key men for instruction purposes.
73 JOP SEER!'!"
~)eclassifi ed by hJS,A. 09-29-2002
pursuantto E.O. '12958, as
ElrTIended FC)IA, Case# 52224

lOP !lEEAiL.
GERMAN CRYPTANALYSIS
During the occupation of Bastern Poland in the fall of 1939, and
during the Winter War in Finland (1939-40), the best men from the
outstations were recalled to the Bureau, because the outstation crypt.
analytic!ioups had proved unable to process accurately ~iid quickly'
enough the current and excessive material. Moreover, a group of
mathematicians (made up .of about 20 men without language training)
was employed at the Bureau during the Finnish Winter War, and
these later formed the nucleus for work on the additive systems.
At the start of the Eastern Campaign, Section E-1 of the Cryptographic
Bureau (later the Cryptanalytic Section of the 353rd Regiment)
was increased to abOut 40 persons, and during the course of the
war to about 90, of whom some were women. The strength of the .
outstations (later the cryptographic section of the evaluation companies)
increased to from 40 to 60 men, women being employed only
in exceptional cases. .
The·intercept companies with the individual air corps ("corps companies"
for short) also had small cryptanalytic groups, but they unfortunately
had to be staffed with poorly trained personnel, who because
of their limited field of work stayed at a low professional level·-­
although their results are by no means to be underestimated.
In the last months of the war, a part of the less qualified personnel
was turned over to combat units.
Although at the beginning of·the war, the focal point of the work
was unquestionably in the cryptographic bureau and the project of
combining all cryptanalytic personnel in a central office inevitably
kept cropping up, the cryptanalytic sections with the Air Commands
went on developing as the war continued, and thanks to the 'regional
systems of the Soviets found themselves in a position to handle the
material coming from their own fronts without assistance.
Section E-1, on the other hand, kept losing significance, and fell to
the l!lvel of an archive and organizational relay point, although it had
in its command an excellent staff of cryptanalysts. Its only remaining
specific assignment was the processing of material which did not
admit of regional processing. But finally, after combined work on
this material had been carried on for a time by the air force and/or
the army, the processing, which had become useless, -was given up and
Section E-1 lost its last particular assignment.
2. SUM!!: SUCCF.STIONS REGARDING THE IDEAL '"ORM 0." OR(;ANlZATION
The attitude to he taken on the problem, "Centralization or Decentralization,"
is determined by the present characteristics of the
Soviet cipher traffic (strong differentiation and regional division of
cryptographic material).
W. WERTHER 10' 5liCll.EI..
In the case of centralization, all otherwise unavoidable duplication
of work could be obviated~ and the personnel could be more logically
used. But the disadvantages would be much greater, so long as, owing
to the length of the Eastern [ront, it remained impossible to carryon
radio reception at one point. The late arrival of the raw traffic at
the central point, due to the insufficient and partly interrupted communications
facilities, causes it to lose its timeliness. Moreover, with
every transmission of messages by teleprinter, additional sources of
error ap'pear which, as experience .shows, can hinder the work and
lower the value of the cipher material. Lastly, the absolutely essential
contact between intercept operator and cryptanalyst is completely interrupted.
.
For this reason the regional concentration of cryptanalytic personnel
in the air fleets for independent processing of their own front sectors
can be considered, in fact, as the most satisfactory solution. A
small working staff exclusively for Questions of organization and training
would have had to be formed from the extensive cryptographic
section of the regiment; all the other analyst.~ would have found more
profitable employment with the air fleets.
Any further subdivision of the cryptanalytic forces, however, is not
advisable, and should be avoided except insofar as there may be detached
companies with special assignments (e. g., long-range fighters
or air defense).
:to ORGANIZATION AND WORKING TECHNIQUE nt' A CRYPTANA'~YT'C SM.,"TION.
a. The Cryptanalytic Section of an Evaluation Company
In this chapter the organization and working technique of the cryptanalytic
section of the evaluation company of an intercept battalion
will be sketched.
Everythiilg said here is essentially ·valid for the cryptanalytic section
of the intercept regiment (formerly E-l of the Cryptanalytic Bureau
of the Air Foree), as well as for the small cryptanalytic groups of
detached companies with sPecial assignments: '.
The cryptanalytic section 'makes up a platoon of the evaluation
company. The head of the section is, when possible, one of the company's
officers (Wachoffi7.ier). The prerequisite is, however, that the
head of the section be an outstanding specialist, and the question of
rank plays but a minor role in this case.
b. The Chief of tAe Cryptanalytic Section (Chief Analyst)
He is the soul of the whole section. The extent of training, pleasure
in the work, and success depend on him. If he cannot continually
show proof of his outstanding professional abilities, he soon loses the
respect and confidence of his men. Experiences with officers who had
74 75

GERMAN CRYPTANALYSIS W. WERTHER TOP 5EeRET
to assume direction of a cryptanalytic group without, or with insufficient,
professional knowledge were always thoroughly disappointing.
For mere organizational activity (assignment of personnel, arranging
work schedules, etc.) without actual professional knowledge leads to
constant wrong decisions and has a most harmful effect.
All cryptanalytic work is a matter of trust; a man cannot be forced
to decrypt, and the actual amount of work done cannot be exactly measured,
since unfortunately, the amount of work spent on cryptanalysis
does not always bear a direct relationship to the success achieved. For
these reasons, if for no others, the chief must be able to judge his colleagues
not only professionally but also as to character.
By means of daily, even though short, conferences the chief must be
in a position to be able to follow continually the work of every individual
man, in order to be available with advice and assistance when
the inevitable stoppages occur. In such conferences,· moreover, current
organizational ills and desirable transfers of personnel will become
evident.
Particularly difficult prohlems are handled personally by the chief
analyst with the assistance of especially good troubleshooters. He is
the man who is always there when.the wagon gets stuck in the mud;
once it gets going again, he cart simply turn his attention to new difficulties
and leave further work on the old system to his colleagues.
Because of security, the work of the cryptanalyst must always go
unrecognized by the outside world. It is all the more the responsibility
of the chief analyst to encourage his colleagues by just praise,
and to see that the accomplishments of his people are appropriately
valued by the "higher-ups" (say, at inspections).
c. Work Shifts
During the war, the personnel of the cryptanalytic section worked
on two (early and late) or three (continuous) shifts. The exact division
of time depends on the amount of work and the size of the space
available, and must be adjusted to new conditions rather frequently.
The assignment of personnel to the shifts takes particular care,
because the abilities of the members of the shift must be carefully
balanced.
d. The Shift Chief
The shifts take care of the current reading of traffic and the simpler
decryptions. The organizational head of the shift is an experienced
and responsible man, who as such is responsible for the entire process
on his shift. He divides the work coming in in accordance with the
instructions of the chief cryptanalyst, and must be able to judge the
difficulty of the work processes in order to recognize and adjust overor
under-loading of his colleagues. Since his organi;ational duties
leave him little time for regular cryptanalytic work, and a long term
of duty would tend to make him become a bureaucrat, it is desirable
from time to time to "change the watch". It is the duty of the chief
cryptanalyst to educate his men so that they see in the assignment as
leader of a shift no particular "social advancement" but only a temporary,
albeit honorable position. The change of the leader of a shift is
neither a punishment nor a sign of lack of confidence, but merely aims
at preserving the usefulness of the individual as a worker.
e. The Cryptanalyst-Specialist (Trouble-shooter)
For rush problems or especially difficult problems the chief analyst
calls on particularly capable and reliable analysts from the shifts.
Generally they work only on the day shift and are continually in
closest contact with the chief analyst, These specialists are given
more or less freedom with regard to working hours and length of working
period,-:,insofar, of course, as inevitable military demands permit.
The continual change of personnel of the specialist group makes it
possible (1) to employ specially capable men in their special fields;
and (2) to raise the level of training of the individual by appropriate
distribution of the work.
Specialization on the part of the individual cannot be avoided. In
and of itself it is desirable. But care must be taken that this specialization
is not allowed to become one-sidedness, so that the worker loses
his necessary perspective.
f. The Clerical Force
The untiring efforts of a strictly trained clerical force are essential
because of the excess of paper and thedanger, which springs therefrom,
of an "editorial-office order." The force consists of one or two workers,
who if possible should have at least a minimum knowledge both of
language and cryptanalysis, 'so that they do not manage, because of
their ignorance, to do more harm than good. The duties of the clerical
force are the'following:
Presorting of the message material received.
Assembling the material by nets on the basis of rnessage designation
(net number, breaking of call signs) by the traffic analysis
section.
Assembling by systems on the basis of known indicators and other
characteristics (recognition books of the cryptanalysis section).
Sifting out of the non-pertinent messages from other fronts and
branches/offices of the armed forces and forwarding these to the
appropriate offices, or destroying them.
76 77 TOP SEeRET

'\
TOl' SECRET GERMAN CRYPTANALYSIS W. WERTHER TOP SE€REL
Filing material which cannot be currently read until work on its
solution can begin, or until the system has been solved.
Transmission of the decrypted' material for exploitation (message
archives).
. Registry of secret papers, teletypes and other material.
In addition to this work, the clerical force c.an be called upon to do
statistical work when necessary.
g. The "Gadgeteer"
It appears advisable to have a worker in each cryptanalytic section
who can make the various aids for additive-eneipherment solution,
such as sliding tables, drum systems, codes, and so on, in simple and
useful forms, and who is always available. By this specia1i?.ation of
one ingenious man much time can be saved, and the neatness and usefulness
of the gadgets can he assured.
a. Presorting and System Recognition .
The already marked message material comeS from traffic analysis to
the cryptanalytic section and is there sorted and identified, first by
the clerical staff and then by the analyst, according to the available
material for recognition of the codes.
b. Decoding
Insofar as the necessary material is available, the message is immediately
decoded, so that there may be no unnecessary time lags, suchas
may seriously reduce the value of the message.
c. Analysis
Unclear material, and material which cannot be directly read (that
is, for which the code has not been broken) is continuously analyzed
by means of all sorts of statistical studies.
d. The Break-in
As soon as the material in a given system has"accumulated to a point
which promises success, attempts are begun to break into it.
e. Analysis of the System and Reconstruction of the Basic Code
As soon as a sufficient number of groups have been determined, attempts
arc begun to reduce this usually relative material to a true
basic, i. e., to reconstruct the original form of the Soviet code. At
the same time the recovered key sequences must be compared and collected
in a unified system.
f. Further Treatment
By reworking the material returning to the cryptanalytic section
after exploitation, the codes are extended by additional recoveries.
During the first years of the war, the break-in could be considered as
the essential crypto-technical process, but lately the emphasis ha.~
shifted more and more to a processing of the system and reconstruction
of the codes.
5. SOME GENERAL WOHKIN(; I·RINelrLf·;~
a. Team Work
The most fruitful form of cryptanalytic work is the collaboration of
a few mutually sympathetic analysts, who naturally get together on
the handling of more difficult problems without direction from above,
and who supplement each other in their intellectual make-up. Alongside
the precise, inexorably logical and constructive systematizer with
perhaps only a fair knowledge of the language, there are the superior
linguist who may not be so good at putting two and two together and
the sensitive artist whose strong point is intuition. When one of
these tires and begins to have his doubts, the common work is carried
on, nevertheless, by the impetus of the others. Discussions bridge
gaps in the ideas .of the individual, and arguments crystallize correct
knowledge and break down unclear· and botched ideas. In short, the
problem is illuminated from all sides.
b. The Space Problem
For this reason the demand which is sometimes heard for individual
rooms as the ideal, in order to assure quiet and intellectual concentration,
is not sensible. On the other hand, a certain spaciousness of
quarters is necessary for the work. The rooms must be large enough
so that the workers do not interfere with each other, and that big
heaps of message and code material do not pile up because of lack of
space, forcing the workers to hunt laboriously for the material they need
at the moment, with consequent loss of time.' Care must be taken in
particular to have extra sorting tables and sufficient space for storage.
The disciplined quiet of an intellectual institution must be guaranteed
in the interest of the work, even though brief but quite necessary
recesses turn the serious room into a jovial gossip-shop. .
c. Statistics
The statistics are to the cryptanalytic expert at once the essence and
the chemical analysis of the message, and the most essential aid in his
work. A careless count can be worthless, leading to false deductions,
and thus seriously delay the course of solution. For this reason the
use of assistants who are employed on the basis of their previous tmin-
78 79 TOil ~!~REI
/

T8f 5EEORET GEllMAN CRYPTANALYSIS W. WERTHER TOP SE'AIiT
ing and limited 'intellectual penetration, as "mere statisticians" is extremely
dangerous and objectionable. Each cryptanalyst must be, required
to make the necessary statistics for his own work. The processing
of very difficult and extensive systems, e. g., superencipherment
with long keys, which requires weeks of mathematical and
statistical work, is, of course, an exception.
d. The ResponsiMlity of the Processor
Each worker is bound to process his message conscientiously to the
point of readability, and to add his initials when he has finished, in
order that the translator and exploiter, as well as the leader of the shift,
may direct inquiries to the right person. The processed messages are
collected and quickly checked by the leader of the shift or sOme specially
designated person, and then turned over to Content Evaluation for
translation.
e. ,Me~age Translation
As long as the majority of personnel in the Content and Final Evaluation
sections do not know the language well enough-and that, unfortunately,
was the situation except in the Regimental Evaluation
Unit--all messages solved must be translated.
At first, analysts were made responsible for the translation of their'
own meSsages. This procedure, however, proved to be most impractical,
for a l;lrge part of the cryptanalytic personnel did not have a
good enough knowledge of the language to make a satisfactory translation
of the difficult and partly garbled message texts:
As a result, mediocre cryptanalysts with very good language ability
were gathered together into a special translation group. Working
under Content }

",.'
GERMAN CRYPTANALYSIS
time, the cryptanalyst is obliged to help himself: current language
problems and obscurities are noted on paper and cleared up at the
next opportunity (as by interrogating intelligent prisoners). The interrogation
officer of the Air Force is used continually, insofar as there
are no other more favorable sources in the vicinity (such as a P/W
camp) which make independent steps more convenient.
Net diagrams, callsign interpretations, and DfF results are used not
only by the clerical force, but also by t.he individual worker in ident.ifying
the encrypted material.
Maps, lists of place names, and time-tables simplify the break-in and
working out of the material. Situation maps and lists, tables of aircraft,
type list.s of all kinds, and military-unit and name files all serve
the ,same purpose.
b. Special Tools
In working on a country for a long time the classical language statistics
(monographic, digraphic, and trigraphic frequencies, etc.) drop
into the background. The few rules of thumb which are still used become
general property.
Novices and less-sure linguists have used list.s, partly prepared by
themselves, in which characteristic expressions are analyzed. Sometimes,
these "crib-lists" have served a good purpose, but they are
looked down on by experienced analysts.
The compilation of a vocabulary from the multiplicity of reconstructed
and a few captured code books t.o form what we may call an "ideal
COdl' book," proved to be particularly useful in filling out partial recoveries.
Such ideal code books were published a number of times
during the war.
In the course of the years, some twenty st.atistical procedures have
been developed, most of which have been used for 'current operations.
The archives of previously read messages are, of great value as
visualization material 'in work on new systems from known' nets and
in further training of cryptanalysts.
Daily summaries in the form of leaflets or card files on the occurrence
of individual systems, on the relationship between systems on
the one hand, and call signs, address and signature groups, place names,
indicators, characteristic headings and characteristic message construction
on the other, complete the list of aids for the cryptanalyst.
c. Explo'itation of Captured Material
Although the German Army intercept service captured a great many
codes during the advances in the East, the amount of captured material
in the Air Force (partly because of the more extensive front) was insignificant,
sO that no reduction in the work load was noticeable. A
W. WERTHER
majority of the captured material was either well out of date (during
the first days of the War in the East, for example, codes were captured
dating' from the year 1935) or already superseded because of compromise.
Moreover, air-ground tables from shot-down aircraft could
very seldom be exploited, because of the short effective period of these
tables (usually only one mission).
The transmission of captured aviation codes from intercept units of
the army and the intercept liaison officers of t.he navy staffs and other
flying organizations was generally assured. ' ,
Sometimes, also, captured orders containing superencipherment
instructions for systems still in use were of great value, since they gave
a clear, insight into the structure of the system in question.
1. COOPERATION BETWEEN THE CRYPTANALYTIC DIVISION AN)) OTHER PROFES_
SIONAL GROupS
a. Cooperation with the Other Groups of an Exploitation Company
A close connection between operators and cryptanalysts has always
proven very fruitful. Frequent conferences give the cryptanalyst
valuable hints for his work. Knowledge of the quality of the individual
operator, the good points of his work or his characteristic mistakes
saves the cryptanalyst from many blind alleys. Especially when attacking
new systems, it is most important to be able to evaluate the
material at hand on the basis of the abilities of the receiving operators.
Occasional talks, in a popular vein, on cryptanalysis and the value of
perfect message material, given the operators by the chief analyst, had
a decidedly positive effect on the zeal of the radio shifts.
The messages arc reviewed and marked by the traffic analysis section
before their processing by the cryptanalysis unit. Discussion with the
traffic analyst can often provide the cryptanalyst with useful hints in
individual cases; on t.he other hand, the cryptanalyst is in a position to
aid the traffic analyst in picking up lost nets, by identifying messages
on the basis of message and system indicat.ors ,and characteristic counts.
In some cases, DjF result.~ can be of notable value, especially where
traffic analysis can giv,e little information.
All card files and other materials of the Evaluation Section can be
continuously used by the cryptographic section for their work. Indeed
it has been shown repeatedly that in the handling of difficult problems
cryptanalysts and exploiters have cooperated and decrypted almost as
a team. The daily work conferences under the chairmanship of the
commanding or executive officer of the section gave the chief cryptanalyst
an opportunity to present hints and wishes for cooperation.
Fundamental for all cooperation is the recognition of the fact that each
specialized section needs the others for its work, and is also needed by
Tap lij;€Ai:r 82 83 1QP lii€RET

TOI' 3EEORET GERMAN CRYPTANALYSIS W. WERTHER TQP 5EERET
them; that each technical specialty is, to a certain extent, a tool subject
for the others; that an individual section can never work successfully
alone. At the beginning of the war, there were attempts for
security reasons to keep the various sections separate from each other
and prevent any exchange of ideas; this insane plan was dropped very
shortl:v.
b. Cooperation of 1M Cryptanalytic Group with Other Cryptanalytic Units
Originally the contact between regiment and section in the field of
cryptanalysis was very close, because the section had neither the personnel
nor the material to meet the demands made upon it. Frequent
borrowing of workers, and conferences, guaranteed the transmission of
new discoveries and techniques.' .
Owing to the differentiation of the cipher material, the often ex'
cessive distances on the Eastern front, and poor communications, the
contact became, in the course of .time, -less close. The sections were
later able to handle their as.~ignments in complete independence.
New systems were exchanged constantly with the regiment by teleprinter,
and their designations were selected by the regiment. An
exceptionwas made sO.that the radio star net.of the intercept service
in the East could be used for the exchange of communications between
the sections. A special cipher system was available for encoding radio
messages concerned with cryptanalysis. It may' be worth mentioning
that at times a Soviet code book was used a... the basis of this system.
Quarterly conferences lasting several days gave the chief analyst of
the sections an opportunity to clear up all technical and organizational
problems with the regiment. .
The three cryptanalytic sections on the eastern front ~aintained an
active interchange of ideas. Frequent visil~ back and forth afforded
~n insight into the work of the neighboring sl.'CtionS and gave a new
mcentive for one's own. Newly solved systems of air armies which
they covered in common were exchanged directly on the teleprinter,
and codes for older and processed systems were compared at regular
intervals. The fact that the key men in all cryptographic sections
had either come from the cryptographic bureau or had worked together
elsewhere for years and were well acquainted led to very stimulating
and loyal cooperation.
The personnel of detached companies of the intercept section was,
in most cases, drawn from the cryptanalysis section; and was later
taken care of by the cryptanalytic section of the exploitation company,
remaining closely connected with the latter in its work..
c. Cooperation with Other Branches of the Armed Forces and Foreign Intercept
Services
Even thougb the field of work of the individual cryptanalysis sections
waS definitely limited by the nature of Soviet cryptographic methods,
an attempt was made to kl.'Cp up a current exchange of opinions with
the corresponding technical sections of other branches of the armed
forces and friendly foreign intercept services, and this led to good
results and a broadening of the professional horizon.
Cooperation with the cryptanalytic sections of the "commands for
communications observations" in the same area was uniformly good.
Again and again, exchange of material betwecn the individual cryptanalytic
sections of the Anny and the Air Force wa..~ arranged. It is
true that it never became very effective because mutual interest in
individual systems was not great, but the characteristics' of the systems,
the resulting methods of attack, and· the general organi7..a.tion of
the work were repeatedly discussed or investigated. Aside from that,
message material of interest was continually exchanged.
In contrast to the Air Force, the Army posts had behind them a great
tradition, although this very tradition threatened to degenerate into
intellectual stagnation and made the organization of the work appear
unwieldy. The successes of the Army became smaller in the course of
the war owing to increased complication of the army systems and very
strict radio discipline on the part of the Soviets. The level of training
and the techniques were approximately the same as in the Air Force.
Cooperation with the Navy was not so close, largely because of the.
difference in technical interests; otherwise, what has been said concerning
cooperation with the Army also applies here.
No cooperation existed with the SS. There were rumors of an
elaborate cryptographic set-up within that body, and sporadic attempts
were. made to recruit key men of the other branches of the armed
forces for it.
Finnish cryptanalysis was carefully and efficiently organized in a
large centr.ll station, had available a multitude of excellent personnel
and obtained correspondingly good results., Cooperation with the
cryptanalysis section of the Finnish First Air Fleet was unrestricted
and led to excellent results.
The cryptanalysis force of the Hungarian intercept service consisted
of over-age personnel and was unadaptable; the results were m",ager.
Although even before the war a disguised Air Force detachment in
Budapest was cooperating with the Hungarians, the relationship could
not be characterized as satisfactory because the Hungarians were not
sufficiently honest.
.,er SE€Ait. 84 85 fer SEEAIiT

lOP :;EER!;T GERMAN CRYPTANALYSIS W. WERTHER TOP !!~IU:T
8. THE CRYPTANALYST
a. Mental Requisites
The prime requisite is a lively interest in the work. A man with~ut
enthusiasm and interest in the work cannot be forced to accomphsh
anything. He is merely an obstructive foreign body.
The cryptanalyst must be intelligent and mentally very alert, but
the ability to associate ideas must be held in cheek by a well-developed
critical faculty. A mere day-dreamer is inconceivable as a cryptanalyst.
The ability to work scientifically, i. e. systematically, is a further
essential. The peculiar character of the profession all too often involves
having the work of days, or even weeks, prove usel~ss ~nd
being continually obliged to try new ways of reachmg the obJectlVe;
in such a situation indomitable persistance is the only resource.
Good knowledge of languages is indispensable. At least, if a man
has no satisfactory knowledge of languages, he must show a pronounced
feeling for languages.
The mathematical ability so often called for or. presupposed does
indeed belong among the essentials, but this talent is not to be confused
with mathematical schooling. The best cryptanalysts with great
analytic and constructive talents have, as a rule, no notion of the
theory of combinations. The few mathematically trained workers on
the other hand often use their knowledge merely to calculate, on the
basis of well-known formulae, how many possibilities this or that system
permits-the system being generally broken by others.
Two other elements must not be forgotten: intuition and--Iuck. I
mean that luck which in the long run falls only to the lot of the competent.
These notes indicate sufficiently that, on the basis of the
requirements set forth, the professional ideal can. 0~1~ be reached by
very few. Hence in the interests of the work the mdIvIdual must have
a definite community feeling; he must not be a mere lone wolf. Most
successes in cryptanalysis are not the exclusive work of an individual
but are group accomplishments, which have resulted from technical
discussion, from mutual criticism, and from an integration of intuition,
systematic work and diligence.
There is no cryptanalyst whose knowledge covers the entire field.·
The reason for this is to be found less in the mental acumen of the
analyst than in the inventors of the systems worked on, and in. the a~cidental
allocation of the individual, usually made on the basIs of hIS
linguistic knowledge. Each one is master only of t?C systems and the
tricks necessary for the solution of the systems whIch he has actually
worked on, and worked on not for a short time-perhaps at some school
or in a course-but in actual practice over a long period. An outstanding
analyst, who has worked, let us say, for years only on the substitution
systems of a particular group of countries, will only· be able to talk
in generalities about machine systems, although it must be assumed on
the basis Df his proven profes.~ional ability that he will be able to hold
his own in this field too.
5
b. Choice of Cryptanalytic Personnel
Selection and replacement of personnel is rendered very difficult by
the striCt demands for secrecy. Special psychological-technical tests
are obviously risky, .while general intelligence tests lead repeatedly to
bad' mistakes. After years of experience in the field of personnel selection
one must come to the conviction that a ten-minute general conversation
reveals the suitability or unsuitability of an applicant better
than the most lengthy and compreh.msive tests. Of course, occasional
errors of judgement cannot be wholly avoided. Many a hopeful novice
reveals himself after a few weeks as an untalented bungler and
many an unimpressive person with obvious deficiencies (inadequate
knowledge of languages, scant general education, and the like) becomes
a successful and well-qualified worker. Thus, for example, an undoubtedly
highly intelligent language teacher, who composed several
textbooks for learning Russian which are recognized as good, failed
utterly as a cryptanalyst. On the other hand a young soldier, a metal
worker by trade, who had never done any scientific work and was
assigned to thc intercept service by sheer accident, became one of our
most effective cryptanalysts.
One factor which must not be underestimated as a contribution to
morale and achievement was the fact that numerous cryptanalysts
were either Germans from Russia and the Baltic States, or Russian
nationals who had immigrated; all these had had their unfortunate
experiences with Bolshevism. For these people, employment in the
cryptanalytic section was not simply a matter of bread and butter or
obedience to orders, but was an expression of strong anti-Bolshevist
feeling.
In the last years of the war, replacements were supplied almost exclusively
by the InterPI

TOP SI!CRET GERMAN CRYPTANALYSIS W, WERTHER "TOP 5EERST
the trade, .8xplanation is not enough. An explanation, for instance,
of how a reciphennent is solved or how a relative code is adjusted to
the presumed original does not, by any means, put him in a position
to perform these tasks by himself. If he cannot himself se~ the problematic
character of his work, if he does not feel the desire to force
his entry into this undiscovered territory by constant questioning .a~d
boring, he will never become a good cryptanalyst. Those who faJl 10
the profession are prone to otTer the excuse that this or that was not
shown them or not explained to them. It will almost always be true
that they did not have the necessary acumen to work out the corresponding
proble'm themselves. As a matter of principle everything is
explained, but it must also be understood. Naturally, however, young
members of the organization are not mere mental messenger boys,
whose time is to be filled out exclusively with sorting messages and
making counts the significance of which' may perhaps not be explained
to them. At the beginning of a long and tedious training it is necessary
that the novice be able to share in the exciting, nay, dramatic
incidents of this work,-that one try to show him the breaking of a
system or the development of a process. Great importance also attaches
to having the young analyst learn to make practical and efficient
use of the manifold aids afforded by all the other sections, for
the best analyst is not the one who works depending upon himself
alone and starting from scratch, but the one who can piece together,
for his own combinations and constructions, the greatest number of
buildirig blocks selected frum the results of the other sections. It
cannot be over-emphasized that the art consists not in working as
"creatively" as pos.qible, but in incorporating as many known technical
elements as pos.qible into one's work.
For this reason it is absolutely essential that the cryptanalyst have
tactical schooling and be acquainted with the work of the various
Evaluation Sections, at least in broad outline. One can only think
with horror of the many fellow workers of those first years who, in
default of the most elementary knowledge of military affairs, did not
hesitate in their messages to subordinate a divisional staff to a regiment
and let the regiment issue orders' to the staff or to start local
reconnaissance planes on a long-range fighter mission--and when
their work was criticized, to assert that what they had written agreed
with the source and if the text was not satisfactory, so much the
worse for the text. One trait of a really good cryptanalyst is his
tendency to conservatism--- the tendency to cling to methods which
have at some time proven good. It is very difficult to convince one's
fellow workers that the methods they have used thus far have led to
the goal to be sure, but can or must be replaced by others which are
better, more logical, and more exact. At such momentB, a certain spiritual
inertia becom~s manifest. Introducing the use of substitution
tableB, for example"or implanting the idea that it is absolutely necessary
to attempt the reconstruction of the original code even though
decipherment with a relative code has been successful; such reforms
require much time, effort, and pedagogical persuaBion on the part of
the analyst responsible.
Formal courses of instruction seemed desirable, but unfortunately
the want of good cryptanalytic personnel was so keenly felt that it
was not possible to release a few good men from their daily tasks to
set up a permanent teaching staff and institute a long,term training
program. All the short tenn and--in the last analysis-improvised
courses in cryptanalysis which were giYen, revealed their inadequacy
and questionable value again and again_ It was really only possible
to discuss the systems briefly and to show the sort of aids necessary in
working them. 'Any made-up problem is after all only an isolated
phenomenon and furnishes training in the use of a particular procedure
rather than in flexibility of mind. That was all, and it amounted to
very little. Thus the short term courses were, for the most part,
merely a means of getting acquainted with the new fellow workers.
The product of the courses was never a "trained" eryptanalYBt. Such
a one develops, as already remarked, only in and by practical work.
As to a text book: no doubt it would have been wise to put into
writing the results of practical experience, fundamental ideas, and
tricks of cryptanalysis in the form of a guide, and to place this in the
hands of not only the novice but the advanced student as a manual
for reference work. This project. was to be carried out after the end
of the war.
88 89 lOP 91!CRET

NSA Cryptologic Quarterly Article:
A World War II German Army Field Cipher
and How We Broke It
Winter 1995 - Vol. 14, No. 4

i
I
I,
UNCLASSIFIED
A World War II German Army Field Cipher and
How We Broke It
CHARLES DAVID
In 1942 the U.S. Army Signal Corps was looking for college graduates to train in radar
work, which was then new and promising. I enlisted, and after, six months of pre-radar
courses in calculus, physics, chemistry, and radio theory at Rutgers University, I found
myselfin Camp Crowder, Missouri, the Signal Corps basic training center.
Once I was there, a classification sergeant informed me that Camp Murphy, the radar
facility in Florida, was overcrowded and that I'd be assigned to some other training.
Checking my academic record and Army Classification Test score, he suddenly asked me if
I had ever heard of "cryptography."
As he thumbed through his manual, my memory reverted to a cryptanalysis course
that my fiancee had taken at Brooklyn College, given by Professor Jack Wolfe of the math
department. She and I would sit in a sunny meadow in Prospect Park, and I helped with
the frequency counts. My reverie was broken by the information that I was to be sent to
Vint Hill Farms Station, near Warrenton, Virginia - close enough to my New York home
and my wife-to-be to please me no end.
Vint Hill was an unusual army camp - in a bucolic setting, with evergreen trees
surrounding the barracks and woods all around. It was a hush-hush place, and we were
constantly warned to keep it so. One of its two parts was devoted to cryptanalysis studies,
and the other was a working radio facility.
The students were men of strong academic backgrounds and achievements. Of course,
there was a large supporting cast of administrative cadre who tormented us with the usual
army routine - drills, hikes, KP, inspections, and the like. However, there was
communion among the "crypt" people as a result of the learning atmosphere and the
intellectual interest engendered by these new and uncommon studies.
Our classes were taught by sergeants. Once in a while an officer would appear from
Arlington Hall, but Vint Hill was an enlisted men's camp and school. We religiously
followed the texts of William Friedman and considered him our mentor. Men left after
unpredictable time periods to join active units in both main theaters of the war. Most
seemed to end up in our own signal centers and were involved with security matters.
After seven months I was called in for an interview, and I was asked if I knew any
German. I had studied the language for two years in high school and was able to read and
translate a newspaper handed to me by an officer. He said that would do just fine, and I
was assigned to a special class being formed.
31 UNCLASSIFIED

UNCLASSIFIED
CRYPTOLOGIC QUARTERLY
The new class of about thirty men was taught by a very bright Sergeant Dineen. He
hadjust returned from Arlington Hall where he had been briefed on two German systemsone
a lower-grade code and the other a medium-grade field cipher which the British had
started to break. We learned about the cryptographic nature of the systems and then
something of the analysis procedures. I knew then that working on them would be
intriguing beyond compare. I found out I was right when I got a chance to work on the
cipher as a member of Signal Security Detachment D, an element of General Omar
Bradley's Twelfth Army Group.
In April 1944, I and other embryonic codebreakers debarked from a large troop ship in
the bombed-out port of Liverpool, England. Our group was brought to London and billeted
near Marble Arch. The next day we were brought to an apartment building on Weymouth
Street that had been given to the Signal Corps for its intelligence work. A number of
comrades and I were assigned to a breaking section working on the German army mediumgrade
cipher. We had been familiarized with it during our last month at Vint Hill and
were told that the British had made good progress with the breaking. The system was
used by all levels of the German army, from army groups on down, seemingly where the
highest-level means (Enigma) were not necessary or available. The encryption method
was a clever variation of the Playfair that rendered breaking very difficult. We called it
NI, short for Non-Indicator, as the early intercepts showed no indicator. To the enemy it
was Doppelkastenschliissel (Two-Box Cipher).
At Weymouth Street it became apparent that all the operational work was performed
by us enlisted men. This contrasted with the British army, where our equivalents were
officers. Our men and officers were mostly professional people and scholars. On the whole
they were older than the average G.!.
Our first weeks were spent on practice problems and perfecting our skills. We also
took a class in military German. Although all of the men had had some past school contact
with the language, this taught us likely army vocabulary. Oddly, however, many of the
people who succeeded best in codebreaking had limited facility with German. The
language experts, both trained and German-born, tended to see more than really was
present in cipher text, and they neglected the more important principles as frequency and
combination, which led to gradual but surer results.
Soon we were thrown in with the earlier arrivals, and we began to work on current
intercepts. Before the 1944 invasion, the enemy signal units on the Atlantic Wall
practiced their cryptography and radio transmission constantly. Often they sent personal
messages, newspaper articles, nursery rhymes, and the like. As they practiced, so could
we, and thus our skills were improved.
When the Normandy invasion began, the breaking proceeded apace. We gleaned both
tactical and strategic information that was coordinated with other forms of signal
intelligence, such as direction finding and traffic analysis. As our armies pressed inland,
it was decided to form a mobile unit to accompany the advancing allied armies. This was
necessary for two reasons. Firstly, our radio-intercept companies had to be near the front
UNCLASSIFIED 32

WWII GERMAN ARMY FIELD CIPHER
UNCLASSIFIED
in order to read enemy traffic more accurately. Secondly, they could send intercepts to us
quickly by messenger.
I was chosen for this unit along with a mixture of the newer and the more experienced
men. The unit was called Signal Security Detachment D, afterwards always S.S.D.D., and
it was commanded by Lieutenant Colonel Charles Allen. We were attached to General
Omar Bradley's Twelfth Army Group, but we always stayed by ourselves in the field.
S.S.D.D. consisted of various sections representing all phases of signal intelligence:
1. Cipher-breaking Team. This was my group. It was headed by Sergeant Howard
Arnold, a fine cryptanalyst from Providence, Rhode Island, who later became president of
a large department store in his home city. Besides continuing his own breaking activity,
Howard supervised the group in a laid-back and thoughtful manner.
2. Codebreaking Section, headed by Sergeant James Wallace of North Dakota, a
skilled and assiduous codebreaker. After the war Jim became a newspaper columnist in
Brainerd, Minnesota. The enemy used code for lower-grade messages and for smaller
units. He and his men were very successful.
3. Traffic Analysis Group was the largest. It studied message headings, radio
frequencies, code signs of sending and receiving units, volumes of traffic, and more to
derive indications of enemy placements and intentions. Led by Sergeant George Bauer, it
was consistently productive.
4. Direction-finding Team, headed by my tentmate Sergeant Leonard Netzorg,
successful Yale Law School graduate. It located and identified enemy units by
triangulating bearings. Len later became an eminent attorney in Portland, Oregon; his
career and views were the subject of a recent magazine article.
5. Emending Section. These German language experts removed mistakes from
interpreted deciphered messages. Much of what was broken was so garbled that it
required people very conversant in the language to make it coherent. Sergeant Hyman
Sobel, a Harvard instructor, was in charge. The group's members were amazed at how we
cryptanalysts broke traffic that was so full of errors,and we were surprised at their ability
to make it understandable.
6. Intelligence Coordination Section. This group collated the information,
evaluated it,and passed reports based on it to the Twelfth Army Group headquarters. It
was headed by a very bright Master Sergeant Samuel Lieberman, whose ability was
respected by all of us.
There was also a small photographic unit, a signal center, and the usual
administrative personnel, motor transport, mess people, etc.
S.S.D.D. landed in Normandy. We started by living in the field and working under
tents. We bivouacked in the countryside near such towns as Coutances, Laval, Chartres,
and Meaux, and in the tiny Lorraine village of Mangiennes. Then came three months in
the city of Luxembourg, where we were quartered in a school not far from the
33 UNCLASSIFIED

UNCLASSIFIED
CRYPTOLOGIC QUARTERLY
headquarters of Generals Bradley and Dwight Eisenhower in the Hotel Alfa. After the
Battle of the Bulge in December 1944, we went through parts of Belgium, entered
Germany at Aachen, and after four months of movement, ended the war in Forchheim,
north of Nuremberg.
As noted previously, all the operational work was performed by enlisted men. Many of
the officers were sent by the Signal Corps to supervise subsidiary functions, such as
transport and billeting, and had little knowledge of our work. Occasionally, men from the
intercept units drifted in and out of the central groups, seemingly to absorb some notion of
what was being done. Of course we had our own intelligence officers, and two in particular
deserve special note for their hands-on attitude and productive work.
The officer supervising my cipher-breaking section was the very erudite Captain
Benjamin Schwartz. He was a family man, over forty-five, who had volunteered to
contribute his expertise to the war effort. Schwartz was skilled in Sanskrit, other ancient
Indic languages, and several modern tongues, and he had headed departments for those
exotic languages in the New York Public Library and the Library of Congress. He
instructed us in cryptanalysis, watched over our daily efforts, and assumed a rather
paternal role toward his men. He was a person who cared, and that meant a great deal.
Captain Howard Mendel supervised the traffic analysis team. He worked at it
incessantly, and he was an intelligent and effective participant throughout. He was
wounded in Luxembourg when a stray airplane bullet went through his side, but much to
the reliefofhis men, their Howie soon recovered and came back.
Soon after we landed, an unexpected development struck our cipher-breaking section.
Many of the approximately sixteen cryptanalysts - no matter how adept they had been in
training classes - seemed unable to cope with a real-life situation in which a solution
might not exist. A substantial portion of the enemy traffic could not be solved, and this
uncertainty created a psychological barrier that stopped men before they started. As a
consequence, many faltered and produced few results.
Four of our men did most of our breaking. They were George Hussey of Bronxville,
New York, and Eric Porter of EI Segundo, California, who worked marvelously together,
Howard Arnold, and this writer.
Though we were the signal intelligence arm of the Twelfth Army Group, S.S.D.D.
traveled by itself in the field. We were an isolated outfit, known only to the intelligence
people. Our security and secrecy were superb, even within the outfit. People in one section
knew very little about the doings in other sections. On a few occasions, senior officers from
headquarters stopped by to express appreciation for our results, and they would mention a
specific case or two that were outstanding.
Our daily intelligence production was notable from the start, but it reached a
crescendo during the three months in Luxembourg. Our deciphered intercepts, traffic
analysis, and direction finding indicated unusual enemy activity before the Battle of the
Bulge began on 16 December 1944. tjudge that people at army group headquarters simply
UNCLASSIFIED 34

WWII GERMAN ARMY FIELD CIPHER
UNCLASSIFIED
did not evaluate these data properly. It probably seemed impossible to them for the
Germans to stage a major armored offensive over unfavorable terrain, especially when
most of their forces were tied up on the Russian front. After the Ardennes offensive was
stopped a month later, the cipher section broke the radio traffic to the German units
retreating from the Bulge. It revealed the detailed instructions to each unit as to exactly
where it should be virtually every minute of the day. With the skies now clear, the Allied
air forces made very effective use of this information.
In January, S.S.D.D. moved again through different parts of Belgium and entered
Germany, remaining there until the end of the war. We stayed near Cologne, crossed the
Rhine at Remagen, camped at Bad Wildungen, and were in Forchheim, Bavaria, on VE
Day. We then moved to the town of Russelsheim, where everyone wondered what our
destination would be in the war with Japan. But that soon ended, and gradually we
worked our separate ways home.
Many of us had a strong affection for S.S.D.D. Our fellow soldiers were often quite
accomplished and thoughtful. There were professors, attorneys, classical musicians,
writers, and businessmen-all on their way tojoin the hopeful postwar world.
A short, personal epilogue: Several years later, I visited Captain Schwartz in
Washington, D.C. He had stayed in the army and had become a colonel in Army Signal
Intelligence. We were happy to see each other and had much to discuss. He thanked me
for my wartime efforts and then offered me an immediate commission to reenlist and come
to work with him. I'm afraid that my destiny was as a civilian, but it was gratifying to
have the praise and appreciation of the boss.
NI DESCRIPTION AND BREAKING
The medium-grade field cipher was called "Doppelkastenschlussel" - Two-Box Cipher
- by the Germans. Because the first messages when intercepted by the British bore no
indicator, the Allies called it the Non-Indicator or NI system.
The NI was used from army groups to all lower units down to company level and
carried both tactical and strategic information. It ranked just below the Enigma, the highgrade
electromechanical machine cipher. The Enigma could not be distributed to the
multitude oflower field units, and thus the NI served as a more practical hand system.
During the North African campaign, the British overran a German signal center and
discovered the nature of the system.
35 UNCLASSIFIED

UNCLASSIFIED
CRYPTOLOGIC QUARTERLY
System Rules
The NI cipher combines a transposition, or more precisely, a seriation of the plain text,
and then two Playfair-Iike encipherments. The apparatus of the system consists of two 5x5
random-alphabet squares (which omit J) such as those in figure 1.
Box 1
Box2
K X N Z Y G S A 0 R
E M 0 B P V F H Z W
L Q F V I B N Y C Q
R A W G U U I E M X
H S C D T K L D P T
Fig. 1. Enciphering boxes
A plaintext bigram, say ED, is enciphered by finding the first letter in Box 1 and the
second letter in Box 2. In this case E is on row 2 of Box 1, and U is on row 4 of Box 2. The
two letters are considered as diagonal corners of a rectangle, and the intermediate cipher
bigram is those two letters which complete the rectangle, namely VR.
Box 1 Box 2
K X N Z Y G S A 0 R
E M 0 B P V F H Z W
L Q F V I B N Y C Q
R A W G U U I E M X
H S C D T K L D P T
Fig. 2. First encipherment
The bigram VR is now itself enciphered just as the original plaintext bigram was and
the resultant diagonals form the final cipher letters - QZ.
Box 1 Box 2
K X N Z y G S A 0 R
E M 0 B P V F H Z W
L Q F V I B N Y C Q
R A W G U U I E M· X
H S C D T K L D P T
•
Fig.3. Second encipherment
In this way EU becomes QZ in cipher.
UNCLASSIFIED 36

WWIIGERMAN ARMY FIELD CIPHER
UNCLASSIFIED
If the two letters of a bigram to be encrypted lie along the same line in both boxes, we
take the letters immediately to the left as cipher values. These we called liners. .For
example, DL= KC. The rectangular cases we called diagonals.
Box 1 Box 2
K X N Z Y G S A 0 R
E M 0 B P V F H Z W
L Q F V I B N Y C Q
R A W G U U I E M X
H S C D T K L D P T
Fig.4. Linear encipherment
For cryptanalytic purposes it is important to see that four combinations of diagonals
(0) and liners (L) exist:
D-D
D-L
L-D
L-L
Plain text
Intermediate
Cipher text
en
FL
NC
ea
HK
TT
The seriation of the plain text consists of writing in blocks of two lines of twenty-one
letters each. For example, using the first line of Heine's poem "Die Lorelei":
gi
uw
XP
Ich weiss nicht was soll es bedeuten
dass ich so traurig bin
and replacing the common ch combination with q:
i q w e i s s n i q t w a s s 0 1 1 e s b
e d e u t e n d a s s i q s 0 t r a u r i
g b
i
n
The vertical bigrams (I-E, Q-D, W-E, etc.) are the pairs actually enciphered:
G G y Q Q D C M A R N E R Q W M B G Q T B
i q w e i s s n i q t w a s s 0 1 1 e s b
e d e u t e n d a s s i q S 0 t r a u r i
U Z Y Z S Z I Q I Q I y A R U F S T Z U N
X B
g b
i n
p 0
yr
oz
HM
37 UNCLASSIFIED

UNCLASSIFIED
CRYPTOLOGIC QUARTERLY
The cipher text is then read off horizontally in groups of five letters for transmission.
GGYQQ
UFSTZ
DeMAR
UNXBP
NERQW
o
MBGQT BUZYZ SZIQI WIYAR
German Communication Protocols
Each German division had its own set of cipher boxes. It was assigned six different
boxes for each day. These were paired in different combinations for each day's eight threehour
periods. In effect, there were eight keys per day.
The German encipherers followed certain conventions, though they grew lax as the
war progressed. They placed an X before and after all numbers, proper names, place
names, sentences, within abbreviations, and at the end of plain texts having an odd
number of letters. As a result, plaintext X had an abnormally high frequency and tended
to mask the identification ofthe usual high-frequency German letters.
The word zuiei ("two") was changed to zwo, and ch plain text was changed to q,
distorting the frequency of q also. The use of occasional "quatsch" (German for nonsense)
sequences was encouraged to distort combinations and frequencies.
All in all, the Germans seemed to feel that the NI system was impervious to timely
cryptanalysis. They had readied a different system on general security grounds but kept
the NI right to the end.
Some Cipher Security Considerations
The seriation (vertical reading of the plaintext bigrams) ensured that the enciphered
bigrams were not same letter combinations of normal German text. The most frequent
ciphertext bigrams certainly did not reflect the most frequent German combinations (en,
er, ei, ie, in, etc.). What the ciphertext bigrams did reflect was the individual frequencies of
disconnected German letters taken two at a time. The most frequent NI cipher bigram had
a good possibility of representing plaintext ee, for example, but this was by no means
always the case.
Even knowing the mechanics of the system, we found that the reconstruction of the
cipher boxes was extremely difficult because ofthe double encipherment feature. No doubt
the German signal experts counted heavily on this.
By using different boxes for each division and by changing the boxes every three hours
of every day, the Germans made the cipher uncomfortably close to a one-time pad systemunbreakable
in theory and practice. Nevertheless we broke it and, generally, in useful
time.
UNCLASSIFIED 38

WWIIGERMANARMY FIELDCIPHER
UNCLASSIFIED
AIDS TO CRYPTANALYSIS: THE INITIAL BREAKS
Each message was preceded by three-letter callsigns of the sending and receiving units
and the time of day. Our traffic analysis teams were quite adept at identifying them. This
plus the assigned radio frequency used aided in sorting the messages by unit - and
therefore by key.
In cryptanalyzing the NI system, we used very large sheets of paper, colored pencils,
and good erasers. These sheets and colors cannot be fairly reproduced in a journa1. I will
describe our analytic tools, show how we used them, and then leave it to the initiative of
the reader to complete the analysis to reach the final plain text.
1205
MXY A-V 0 L V V K X R K C X V R B X A B A S K D
URT D F X E G K M N Z I W B T A W P F Y 0 K E
B- G K S Q A V I S K S N U T E K 0 C K C G F
V U A Z N R I M Z R W I F G K K K L T T D
c, W P N M Y Y K G C C D Y M W 0 K F I S M Q
T D Q Y C X K D Y P 0 P I S Z F L S 0 A E
D-U Q D 0 U N K I N D H G 0 Y P H M K N Y B
I Q M Q Y D K B F A G Q D M D A A I 0 Y F
E-D 0 E R F B P V P U
L K D I 0 R E M Q 0
1215
REX F-M U M V I B V 0
IXY P Q K 0 I W D U
1240
ZBT G-K L 0 A Z W S E Z U C K S P K 0 T X C y U
QLS K S L F Q M F D X D P Z Q X N M 0 V K D S
H-C X S Z 0 K W
K C A C M K P
1305
RLS 1- K N D C V M K S A N I L Y S M C A P W B Q
BNQ K s U P 0 K Z K A Q I K C L S K W S X C G
J- Y K C S I U T 0 S G M D 0 G K K C K o 0 H
W L D M Z Z P K A S Y A R Z K Q M K V Z B
K-N C F Y K F
L U T T Z A
39 UNCLASSIFIED

UNCLASSIFIED'
CRYPTOLOGIC QUARTERLY
1340
DEF L-K U G Y X K W S K R M K A U 0 V H K K N C
GHI K K B W W Z H M M Z U K E B K B G K F I P
M-V C G 0 S 0 L C K 0 K I W A S V K F S U A
B Q Q 0 V S R P L K Q I B F R M K S X I N
N- S N 0 0 V A
A Z M K R P
1350
paR
CLV
1415
QZB
LTS
0- T C K U
N U K 0
P- V D L V V K B U 0 U S H W V D Y E B Q 0 G
D F X E G K Z W Z K A Z X D F P D 0 A Z Q
Q-K F U K y L K U G 0 K I X W Z L a X F K C
K P 0 K E W I o V K T M M X C S N R X B P
R- X P B T M K F a T L S C 0 A N I M P S P Z
N Q F B D K S Z Q p A A B R I I P Q A X T
Fig. 5. Transcribed messages for a single period
Usually we needed a sufficient number ofletters in the same key to make inroads into
the cipher. We were delighted if many more letters arrived for a three-hour period, but
often not enough traffic was intercepted to afford us an entry.
To illustrate the solution of the cipher, I have composed a sample problem of eighteen
lines of cipher text supposedly intercepted from units of one division during a three-hour
period. Also listed are the times of transmission and the callsigns of the sending and
receiving radio stations. Each pair oflines is given a line identification letter (see Fig. 5).
The messages have been manipulated to allow showing a number of techniques in a
relatively short space. This sample is much less difficult than the messages we
encountered, although the language is typical of the German radio traffic ~fthe time.
Knowing how the system worked, we were able immediately to rewrite the intercepted
messages in two lines of twenty-one letters each. Once the messages were in this form, we
made a bigram frequency - one of our most useful tools. The count was made in a 25x25
matrix on graph paper.
Each line of the problem was given an identifying letter at the left, as can be seen in
-figute-6: "When a bigram was entered on the frequency count, that line-identification
letter was entered in the appropriate square instead of a tally mark allowing us to locate
the occurrences rapidly (see Fig. 6).
UNCLASSI FIED 40

wwn GERMAN ARMY FIELD CIPHER
UNCLASSIFIED
With the frequency count as a guide, we attacked the messages using a technique we
called anagramming. This started with an assumption - an educated guess - followed by a
good deal of trial and error. The intent was to substitute these plaintext assumptions
throughout the problem, check surrounding values, and search for clues to expand our
guesses.
We could not immediately start reconstructing the boxes even when our assumptions
were corroborated because of the double-encipherment feature. The middle bigram is
unknown, and a workable number of plaintext values must be ascertained before a start
can be made in forming the boxes.
In the frequency count, we find that KK cipher text stands out with the highest count
by far. We can start by assuming that it represents ee. We replace KK with ee throughout
the text and see where it leads us.
The Germans often sent very short messages that reflected basic military necessities
and which were therefore constantly repeated. The most common six-, eight-, ten-, and
twelve-letter messages were known to us. Curiously, we were almost never given
information about the military situation that might yield more specific probable words for
our attacks. I don't know why. Perhaps it was security, perhaps ignorance, perhaps lack of
time.
Note Line 0 in our sample problem:
Line 0-
T C K U
N U K 0
To the experienced eye, this is a dead giveaway. The Germans were constantly asking,
"What is your position?" or wie lage. The phrase might be preceded by a "please" or
"request" or an addressee, but time was critical, and the eight-letter message was common.
We thus have assurance that our KK = ee assumption is probably correct, and we
have:
Line0-
w i e 1
T C K U
N U K 0
age x
Our initial assumption has grown: We now have plaintext pairs wa, wg, and lx.
The Germans used many stereotyped openings. With experience, we cryptanalysts
could recognize them. For instance, messages frequently began with an ("to") followed by
the person or unit receiving the signal.
We are fortunate in having three of our practice messages begin with KK cipher text.
In German military text, about 95 percent ofthe time a message starts with e, the opening
41 UNCLASSIFIED

UNCLASSIFIED
CRYPTOLOGIC QUARTERLY
A B C D E F G H I K L M N 0 p Q R S T U V W X Y Z
A I L GM BM AN R I A
B A I I lwR P
C I R J A BGH J M
I
I!
F
GL
M I B KO C
MQ
P
D OJ R A APP E 0 C I
E EGP B
F K B C E Q r,tR K Q
G L C
DM
P
J
B
BQ
J
H D J DL P
I DI
BEl
MR Q
C J
K Q CL I D ~ ~ DM
L G JM Q B ~C
Q
L ~!U
R M I}Q Q ~
I
JL
LL
M CD R C FI FR 1 L
CJ
N D DI LR K 0 Cl I 0 N
0
EJL BJ GH
rJp
0 MO N Q 0 J M F J fR-
P CD E ERR 1 GR
Q C I 0 B
R E A A L
S NPR
BHJ G I I
R
BJ
L
AC G BM M M
T R B 0 G J R
U L L ~Q BOM LO EO F G P D J
V
LM
AFP AP 8M FI BM
P
W M L G H C C PQ
X H AQ R Q G AL
I
Y Cl G Q D CP K JL C D
Z HQ G R G
UNCLASSIFIED 42

WWIIGERMANARMY FIELDCIPHER
UNCLASSIFIED
words will be one of four: erbitte C'request"), eigene C'our, our own"), ein C'a"), and eins
C'one"). Let us see how this works in our text.
Ifwe try erbitte in Line I, the final e falls on ciphertext KZ, which has a high frequency.
(Frequencies are always our strong ally.)
Line I -
Line L-
e r bit t e
K N D C V M K SA.
K SUP 0 K Z K A •
e
KZ also occurs in line L in position 6. This is a perfect opening for eigene:
e i g enee
K U G Y X K W S K R M K A .
K K B W W Z H M M Z U K E .
e
e
Although these are only the upper values of bigrams, when they are substituted
throughout the text, we gain opportunities for assumptions for additional anagramrning.
For example, bigram CP in Line I has a rather high frequency, and it is a good assumption
that the bottom plaintext letter is e.
We now examine other lines, with our assumed plain text entered, and see what can be
done:
Line A -
e
e nne
VDLVVKXRKCXVRBXABASKD
DFXEGKMNZIWBTANPFYOKE
e
Units in the field constantly sent reports to various headquarters. German operations
officers in a unit's staff (G-3 in American nomenclature) had the designator 1a. Messages
to higher headquarters often began "an roem eins Anton" C'to roman numeral one Anton" ­
"Anton" being the German phonetic equivalent of our "Able"). Line A has several values
that fit this possibility:
Line A -
anxroernxeinsxanton e
VDLVVKXRKCXVRBXABASKD
DFXEGKMNZIWBTANPFYOKE
e
Often this opening was followed by "enemy something or other" as "enemy tanks, or
planes, or troops." ("Enemy" is "Feind" [noun) or "FeindIiche" [adjective] in German.)
That seems a likely entry here because of the KK (ee) second from the end on top and
around the bottom where "Feindliqe" connects with it. Now we have six more probable
equivalents to substitute throughout.
43 UNCLASSIFIED

UNCLASSIFIED
CRYPTOLOGICQUARTERLY
Line A -
anxroemxeinsxantonfei
VDLVVKXRKCXVRBXABASKD
DFXEGKMNZIWBTANPFYOKE
ndliqe
e
Let us examine one more short message to see ifanything can be made of it:
Line F -
Line F -
t tea
MUM V I B V 0
P Q K 0 I W D U
That first word just has to be bitte ("please"). But please what? A common request was
for a situation report, and a frequent sixteen-letter message was therefore bitte lage
meldung ("situation report, please"). Checking the frequency chart also shows higher
counts for a few of the cipher bigrams that accord well with their plaintext equivalents
(e.g., II = e d has a count of 5 and VD = an a count of 3). We always looked for frequency
indications that tended to confirm what were still only assumptions. Thus we have eight
more probable bigrams:
bit tel a g
MUM V I B V 0
P Q K 0 I W D U
e mel dun g
It was a good break if we found two messages with the same beginning. It was
especially helpful if the beginning was longer than twenty-one letters and thus continued
on the second line. Such a case may be seen in Lines A and P. We have already
anagrammed some of Line A, and it seems as though it may share the first twenty-seven
letters with Line P. Note the six-bigram repeated block at the beginning of Lines A and P
and the repetition of vertical bigrams at positions 1 and 14 of Line P.
Line A -
anxroemxeinsxantonfei
VDLVVKXRKCXVRBXABASKD
DFXEGKMNZIWBTANPFYOKE
ndliqe
e
Line P -
anxroemxeinsxantonfei
VDLVVKBUOUSHWVDYEBQOG
DFXEGKZWZKAZXDFPDOAZQ
ndliqe nd
Thus it seems we have another fifteen upper letters to substitute in the problem.
One of the greatest helps to the cryptanalyst is to know what the enemy is likely to
talk about. There were plenty of the German equivalents of "enemy," "aircraft," "troops,"
"armor," and so on. But by far the most common words were the cardinal numbers: eins,
UNCLASSIFIED 44

WWIIGERMANARMYFIELD CIPHER
UNCLASSIFIED
zwo, drei, etc. Supply reports, casualty figures, radio frequencies, times of day, location
grids, and much more all required numbers.
Often when no other openings were visible, numbers could be spotted in the middle of
messages - after some judicious assumptions based on frequency and combinations. The
ten digits were frequently used in groups (e.g., four digits for the time of day plus uhre,
"hours") and were separated one from another by X.
Security violations and operator mistakes greatly helped us. Of course, we were
always looking for that rare happening - the same message sent in plain and cipher textbut
that was rare.
Let us examine Line G ofthe problem:
Line G -
Line G -
e e ie
KLOAZWSEZUCKSPKOTXCYU
KSLFQMFDXDPZQXNMOVKDS
e
e
We already have some letters of Line G, one of them being an initial e. Now look in
figure 5 at the header of the message:
ZBT
QLS
1240
The alert cryptanalyst now rubs his hands in glee because he realizes that the careless
German code clerk has included the time of day at the beginning of the message. (This
occurred once in a long while.) We now have the following:
einsxzwoxvierxnulluhr
KLOAZWSEZUCKSPKOTXCYU
KSLFQMFDXDPZQXNMOVKDS
e
e
There is a slight problem here because the code clerk accidentally omitted the X after
null, but that is seen when uhre fits into the bottom e of cipher KK.
The above examples should give a good idea of how the initial plaintext wedges were
made. Again, I caution that the sample problem is contrived - it was never this easy. Very
few of these entry points, if any, appeared within the same three-hour period. It took a
very patient cryptanalyst to find correct plain text in the average set of messages.
This involved daring assumptions and detailed tracking of surrounding bigrams to
find promising combinations. Trial and error, persistence, and some sixth sense could lead
to progress. We stuck with a three-hour period as long as it seemed to show promise - a
large volume, a good frequency count, likely plain texts. Conversely, we abandoned a
period for a new one - usually on the basis of instinct and experience - when we were
getting nowhere.
45 UNCLASSIFIED

UNCLASSIFIED
CRYPTOLOGIC QUARTERLY
Once a sufficient number of bigrams was recovered - one cannot quantify it exactly ­
we set about trying to reconstruct the cipher squares, a process we called "boxing." This
could be the most daunting task of all. As the squares were completely random, we did not
get help from any pattern or keyword.
The first step was to make "encipher" and "decipher" charts. These were large sheets
with 25x25 matrices, each cell with four quadrants (see Fig. 7).
A II
" c II
\I I II
T·: GI:
I' \I t
B
II I A I /I I
B I I I 1M II I
I II I II 1
C I II I 5
..
II
I II BI I /I
I Ii ID I II I Mil
I II A I I 1101 II . I
" E 11 p;
E I I Y II I I I K II I K II I
\V I L I II I II K I II Z
"I
I I. I
I Q II
FI
Ii II I"" II I E II ~ I
AI II II /I I Ii P I Ii . I I
GI
, II I, /I I Q II I !\ Ii I /I 10/1
I II Ii Ii Q I /I P I • /I I I! li I /I
E\
I II II t II 1 /I I I /I
I Ii Ii I Ii . I II I I II
I [ I Z II I G II II I Ii I C /I I /I I C /I
I W I II L I II I II P , II I II r I II
1-: I
I /I I II I /I I II I II I II
I II I Ii II I II I Ii I II
Fig.7. Portion ofencipher chart
The charts were over a foot square and were preprinted for us in horizontal sets of two,
which made it easier for us to fill in and work from both at the same time.
In the encipher chart, the bigrarn coordinates of the matrix represented the plain text,
with the cipher equivalents written in the appropriate square. The first letter of the cipher
bigram was written in the upper right quadrant of the square, and the second letter in the
lower left quadrant, thus serving as a reminder of which letter belonged in which box.
The decipher chart was the reverse. The coordinates were the cipher bigrams, with the
plaintext bigrams written in the upper right and lower left quadrants of the inner squares.
The upper left and lower right quadrants were reserved for the unknown intermediate
bigrams of the cipher which might be discovered as we progressed with pencil and paper.
These charts now served as the the software for the computer in the cryptanalysts' minds.
With graph paper and pencils, the problem then was to somehow string these letters
together so as to recover the original cipher boxes. For a start we used numbers to
represent the middle letters, and then by using other related values we tried to "hook"
UNCLASSIFIED 46

WWIl GERMAN ARMY FIELD CIPHER
UNCLASSIFIED
some of the letters together. Except in the unlikely event of a very great amount of
anagrammed plain text, this became an eye-twisting exercise in frustration for several
reasons.
First, we had no idea of the middle bigram. Second, as I explained earlier, the final
cipher bigram can be the result of four possible enciphering combinations: diagonaldiagonal,
liner-diagonal, diagonal-liner, and liner-liner. Third, we had no idea of which
letters in each box were on the same line, or in the same column, or opposite which line in
the other box.
Fortunately, the inherent properties of the boxes and the enciphering method offered
ways to help reconstruct the boxes. I will use the cipher boxes of figure 1 to illustrate the
three most useful phenomena.
1. Reversibles - If the middle bigram of the encipherment is a repeated letter, the
result of the second must be the reverse of the original plaintext bigram:
ed = HH = DE
This can result only from a double diagonal, which is a clue we really need in our
boxing effort.
2. Reciprocal - Assume a plaintext bigram enciphered via two diagonals. If the
reverse of its cipher bigram happens to be a plaintext bigram, its own cipher equivalent is
the reverse of the original plaintext bigram:
(1) ne = AW = XM
(2) mx = WA = EN
Thus if we find two of our anagrammed bigrams 10 this forward-reverse
relationship, we know that they can result only from a diagonal-diagonal encipherment.
We encircle these in red on the encipherment and decipherment charts. Eliminating the
possibility ofliners is invaluable in rebuilding the boxes.
3. Appendixing - "Appendixing" aided the analyst in determining which letters
were on the same line in a box. Ifany letters are on the same line (e.g., K, X, N, Z, or Y in
Box 1 of figure 1) and are combined with one particular letter in Box 2 - say the letter E in
the fourth row - then the first letter of the middle bigram must be the same for all the
bigrams:
ke = AR
= XX
xe = AA = EX
ne = AW
= XM
ze = AG = UX
ye = AU = XR
47 UNCLASSIFIED

UNCLASSIFIED
CRYPTOLOGIC QUARTERLY
When the middle bigram is reenciphered, since the first letter (in this case A) is always
the same, the final bigram can consist of only one of five values in each box, instead of the
usual twenty-five: (in this case U, I, E, M, or X in Box 2, and X, M, Q, A, or S in Box lor
letters to the left when a liner is involved).
So ifwe find a pattern of repeats going down a column of our charts, there is a greater
than normal chance that the corresponding outside letters on the left are on the same line
in their box. This can be fortified ifanother column shows a similar pattern. None of this
is certain, but it bolsters the odds.
From this point, the cryptanalyst resorts to trial-and-error boxing. If the reader has
experience with a particularly difficult Playfair cipher, where it appears that some letters
must be all at once on the same row, in the same column, and on the diagonal with others,
he will have some appreciation of what we faced.
Common Boxes
As mentioned earlier, each German unit was supplied with a group of six boxes for the
day. Since two boxes were necessary for each of eight three-hour periods, some of the boxes
were used more than once. For instance, Boxes 1 through 6 might be used as follows:
Time of Day
Box Combination
0001-0300
0301-0600
0601-0900
0901-1200
1201-1500
1501-1800
1801-2100
2101-2400
1&2
3&4
4&1
5&6
3&5
2&6
5&2
6&3
The difficult and crucial breaking was of the first workable period that appeared
during the day. This was not necessarily the 0001-0300 slot but the first period with
enough text to attack. We called that the original period. Which it would be was not
predictable; no period was regularly the busiest. After that a search was made for other
periods that used one of the two boxes now known. Ifone was discovered, its period was a
rather easy one to solve.
Locating a common box in the double encipherment was not simple. A period had to be
anagrammed and boxing started before there was a basis for comparison. However, once a
common box was spotted, an experienced analyst could quickly reconstruct the second one.
I would like to discuss the major reasons for the NI cipher-breaking being so difficult
and daunting.
1. Volume: The enemy changed its boxes every three hours of every day. The
quantity of cipher text available in a three-hour period was often insufficient to work with,
or just marginally sufficient, and might not bear fruit.
UNCLASSIFIED 48

WWII GERMAN ARMY FIELD CIPHER
UNCLASSIFIED
2. Peculiarities: Even with adequate volume, a particular text might have a
makeup that frustrated continuity, even after sensible beginnings. Worst of all was an
aberrant frequency count, which would result in interminable false starts. Though this is
common with limited message volume, many longer texts displayed abnormal frequency
indications. Despite this, we had the feeling that, given time, we could break into most
problems, which brings up the next obstacle.
3. Time strictures: Messages enciphered in NI dealt with both tactical and strategic
matters. However, after a day or two, the intelligence became stale, and we had to go on to
new and fresh material. Working under this kind of pressure proved impossible for some
of the men.
4. Garbles: This was the greatest obstacle. The German cryptographers made
mistakes, their radiomen transmitted wrongly, and our interceptors made errors in
picking up what was often a weak signal. At times we had the same messages from three
or four intercept-companies, and the variation could be most marked. If breaking
assumptions are based on wrong cipher values, the analyst is dead in the water from the
start. Sometimes we displayed an almost sixth sense about incorrect letters, but garbles
greatly hindered us.
A Simplification - Single Encipherment
With the invasion of Normandy in June 1944, much of the enemy traffic began to be
enciphered only singly, the second, double encipherment being omitted. The German
communication experts perhaps realized that the double encipherment took too long and
was too prone to error at both ends to use in combat situations.
To illustrate its use, here are the opening words of "Die Lorelei" singly enciphered in
the boxes of figure 1:
Y Y I V Q D L A Y N L U X L P W Q Y V T F
i q w e i s s n i q t w a s s 0 1 1 e s b
e d e u t e n d a s s i q s 0 t r a u r i
U S .A R T A Q C Y X Y A Q X X C K K R X G
Ct: YYIVQ DLAYN LULXP WQYVT FUSAR TAQCY XYAQX XCKKR XG
It will be seen that our task was much simplified. The diabolical middle bigram no
longer exists, and the analyst can use a reciprocal process of simultaneous anagramming
and boxing. Some salient helping points are as follows:
1. When enciphered, a plaintext letter must result in a different cipher letter in the
same box. Thus, for example, bigram ab cannot possibly show a cipher B on top or a cipher
A on bottom. This helps prevent wrong anagramming.
2. Single plaintext values allow a start to be made in boxing. If we know that
plaintext u- is cipher XV, then we also know that X in Box 2 is on the same line as u in Box
49 UNCLASSIFIED

UNCLASSIFIED
CRYPTOLOGIC QUARTERLY
I, and that Y in Box 1 is in the same column as u in Box I, or in the same line adjacent to u.
Single values are far less useful in double encipherment.
3. Plaintext assumptions lead more quickly to boxing contradictions than they do in
double encipherment, letting us discover anagramming errors much earlier.
Unfortunately, while these aids are valid, they were rather moot in practice. Often the
reason was the lack of sufficient traffic in any three-hour period. Add to this the numerous
garbles, and breaking the cipher was still difficult - especially in a usable time frame.
Nevertheless a large volume of the single encipherment was broken in time to be of use.
Because ofsecurity necessities and our isolation, we were largely in the dark as to the use
ofour information, but we were assured by officers from General Bradley's headquarters
that it was of constant and great value.
To sum up, I found that breaking the NI cipher system was a complex and often mindbending
process. It would be interesting to learn if it were the last of the "pencil-andpaper"
systems used by a major army in a major conflict. It was tempting to think of it as
"interesting" or "intriguing," but in wartime that seems incongruous. Perhaps now, many
years later, we can study it with a greater degree of academic equanimity.
(U) Mr. David was born in Brooklyn,
New York, and graduated from
Brooklyn College in 1941. After taking
graduate courses at Columbia
University, he enlisted in the U.S. Army
Signal Corps in 1942 and served as a
cryptanalyst until his discharge in 1946.
Mr. David then went to work as a sales
representative, from which he retired in
1988. He presented a talk on the subject
of this article at the 1994 Cryptologic
History Symposium.
UNCLASSIFIED
50

NSA Cryptologic Spectrum Article:
The German Cryptologic Effort 1918-1945
Summer 1975

~
(b) (3)-P.L. 86-36
.,pproved for Release by r\JS,A, 0
~]9-29-2CHJ8 FOI.A, C:ase # 5222"
The German Cryptologic Effor't
1918-1945
Betu'een tbe two world u'ars. six ma.;or cryptologic
.rert·ice.r and hureaus evolved within German;'. Three
u'ere responsible mainly for foreign diplomatic systems,
and the other three' repr~sentinK each 0/the branches of
the armed serl'ices ·-for exploitin!!, counterpart forei!!,n
militar.''1 systems. Sel'eral additional cryptologic
orl?,anization.( were also estahlished to u'orR al(tJimt
s,'Ystems used. for example. by enemy a/!.ents and (or
encipherinx weather traffic. 1~ the area' of
communications securit.'Y. five of these six orxaniZ4tions
u'ere responsible for desixning and testinx their ()u'n
cr,yptoxraphic s."lstem.r, and for insuring tbeir securit."1
when used by associated armed forces units or hy the
diplomatic sen·ices. All of these agencies and h~re(Jus
It:asted side h;' side u'ith more or les.1 equal authority.
There u'a.r no central conrdinatinx point to fuse, et'aluate,
and report German communications intellif!,ence. or to
safeguard ol'erall communications s.ecurity.
This JitUtJtion also pref'ailed for the maior portion of
World War ll. In the autumn of 1944. hou'III'er, an
attempt was made b."l the German HiXh Command to
establish a single cryptologic policy and to im'est one of
This discussion of German cryplololl)' is taken mainly from an
Armed Forcn Security Allency Council (AFSACI study produced in
1')')0. enlitled: "The Consequences of l.ack of Coordination am"n!:
the German Cryptolollic Services." It is presented in S/Hctnlm to show
the fr'j(mented German cryptolollic effort from 1918-1945. and to
~how proNems such an effort fostered and its consequences lU the
German war effort.
the existing orxanizations with the responsihility for its
implementation. Special empha.ri.r u'as placed 071 tbe
authority /!,il1en this agency to rull! upon the seL'uritJ of
cryptof.raphic systems for both diplomatic and milita'.'1
use and to control the del'elopment and use of
cr.yptanal,;tic aids and devices. Interdepartmental
;ealousies, howef'er, were not easi('1 overcome, and it was
not possible durin Ktke feu! remaini,,/!. monthJ ofthe War
to effectit'e~y implement thiJ plan.
German Cryptologic Organization,
1918-1938
Cryptolol!,ic Bureaus
The three cryptologic bureaus which existed during
World War I continued in operation after the Armistice.
The responsibilities of these bureaus were clearly defined.
and they functioned, so far as can be determined. as the
main cryptologic organi7.ations within the German
Government until )933.
The first of these, the Cipher Bureau ofthe Ministry of
Defense, was responsible for workinJt on foreign army
cryptographic systems. The second, the Cipher Bureau of
the Forei,gn Office. was assiJtned foreign diplomatic
systems, and the third. the Cipher Bureau of the German
Navy. forei}(n navy systems. All three were also
responsible for insuring the security of counterpart
German communications.
lIs'ifJFJIJ: '111\ t.f.Jl.IINT (I Ja.4,4EL1 UNt'l .£iCRE"- 25
~.,

Despite the d~arly defined mission~ of these bureaus.
rivalr\' between the first two he~an almost immediately
after the Armistin:. This rivalry be1:an when th~ Defense
Bureau involved itself with diplomatic systems of forei,gn
,governJl1~nt~. dearly a n ar~a reserved to th~ Forcil!n
(Hlice's Bureau. Althou,l(h a number I)f reasons were
,civtll in iltWmpts to justify this encroachment. the\' did
not satisf\ the forei~n Office. :-.ievertheless. th~ Cipher
Burtau of the Ministn of Ddense wntinued to work in
the diplomatic area. thus duplicatinl! to a considerable
extent the work of the Forei~n Office. I ntercept stations
of both bUrl:aus were assi,l:ned diplomatic tarJ(ets. and
tension and rivalry between the two steadily intensified.
The Cipher Burtau of the German ~avy. however.
limited itself strinly to forei1:n naval traffic. and as such
did nnt encroach upon responsibilities of the other
bureaus. nor they on its mission.
F..rtflh/iJlmJI!1l1 f~rthe Ff)r,cchun!:samt in 1933
In March. I

Radio Defense Corps. was responsible for the
identification and "elimination" of enem)' radio a,gents.
Another, the Weather Service, involved itself with
weather cr)'ptol{raphic systems. A third. the Postal
Service. was ~iven the task of monitorin~ telegraph.
telephone, and mail communications, And the fourth. the
Propa~anda Ministry. was responsible for the intercepdon
of forei~n radio broadcasts.
The German Cryptologic Organization
in World War II
The StruKx1e for Authori~y
By the be~innin}!: of World War II. Germanv had six
major cryptologic or}!:anizations. each more' or less
independent of the others. This situation prevailed. to onc
de}!:ree or another. throu~hout most ofthe war.·
But an attempt was made during the war to place this
fra~mented effort under one central authority. It evolved
from the realization by persons in the G~rman High
Command. and in some of the t:ryptologic or~anizations
as well. of the need for a centralized authority in
nvptologic matters. partimlarly in regard ro safe~uar'ding
the security of German cryptographic systems and
procedures. Attempts were subsequently made to
inaugurate an over-all policy, and to establish a central
authority. but with onlv partial success.
The Armed Forces High Command Cryptolof:ic
A/tency I was selected to provide this leadership. and in
September 194.'1 it was ordered that this Agency must be
consulted. and approve. proposed introductions of new
ayptowaphic systems bv any branch of the armed forces.
Also. in Au~ust 194.1. this Al{ency was ~iven the
responsibility for chairin~ a working committee
responsible for o... erseein~ the testinl{ of all German
cryptllg-raphic systems. Under the chairmanship of
General Gimmler. numerous high-level meetings were
held. attended by representatives of all the l"fyprol(l~ic
organizations. General Gimmler. however. found it
necessar~' to dilute responsibili ties and authority of [he
workinf: committee, and to assure the cryptolo!/:ic
or~anizations that their own prero~atives would be
respected. In fact. when C

:iECRE~
Anlllher instance conn:rnt"d the securit\· of the main
(jctrn,ln lfvp((l~raphi( machine the E~iJ.!ma.~ Each'·
hranch llf the German armed forces ha

Doenitz went even further, ~a\·jnl: he had never heard
of the Army unit. and had no i~f()r'mation abuut the Air
Fone's lIr~anization. si nee these matters were of .. no
interest to him." Ribbentrop realized that the forei~n
Office and (joerin~'s l-"or.rcbu1lgsamt wtre: (Overing the'
same field. but he c1airnt-c:1 that the texts (Ifthe latter were
less clear and often inaccurate. Hitler himself. acwrJing
to Ribbentrop. expressed linle interest in the German
crypwlogic effort. noting that Hitler "did not like this
type of intelligence very mU('h and ... it was he:m~r tlJ use
... (omrnon sense.
Conclusions
Baron von Ribbentrop, Minister of Forei~n Af.
fairs, reco~nized the fragmented nature of the
German cryptologic effort, noting that it "was.not
well directed," and that when be beld discussions
to consolidate it "nothing happened."
them to the maximum extent possible. JodI. for example.
noted that the Furschunpamt was "Goering's affair."
and "Keitel described the Forei~n Office. about which he
admittedlv knew nothi ng. as "extremely secretive Jnd
jeJlous about everything ~heir bureau produced." He also
referred til the ForJl'hungramt as the "third competitllr"
and felt its reports were chosen on an "erratic and irra·
tional basis,"
From the: foreg()in~ discussions. it IS seen that
Germany. from 19lH to llJ4'i. had nil national
cryptologic polk)'. Rather. six major or~ani7.ations. and at
least four of lesser significance. wndurred its cryptllllll(ic
husiness in an atmosphere of rivalry and suspicion. None
had clost association. much less coordinating authority.
with llr over any (If the others.
This situati~n prevai led. to one degree or another.
throu~h(lut most of World War II. severely hindering
Germany's, war effort. and resulting in redundant and
wasteful effort and missed opportunities. Although
German leaders reco,l(niled these shortcomi n,!(sas far
back as 193.', it was not until late in the war that a
concerted effort was made to correct them. By that time.
however. it was too late to effectively implement such a
national policy. and Germany continued to suffer to the
end of the war wi th a fra~mentedcrypt()lo~ic effort.
I
Ijoined NSA in 1956; since then he
has worked mainly in the collection and SRA fields.
and at present With the NCS Press. He has contrib.
uted a number of, ~rticles to Spectrum and other
Agency publications.
(b) (3)-P.L. 86-36
II 2)'1)• .1: "Iz' totu,.l" '(:JJ:'z~JtJl:J.!i UNI.Y ..sECRET 29

NSA Cryptologic Spectrum Article:
The German Comint Organization in World War II
Spring 1978 - Vol. 8, No. 2

UNCLASSIFIED
David Kahn
The German Comint Organization
in World War II
A German interpreter hunched over and listened
intently to the Russian voice in his earphones. It came
from a loop of wire that members of a wiretapping squad
had set out two weeks before to intercept Soviet field
telephone conversations.
All around him, that winter's day early in 1942,
German forces tightened their steel grip around
Sevastopol, a key port on the Black Sea. But the Russians
defended their Crimean fortress with toughness and
tenacity. Like a bear swiping at his tormentors with his
paws, they struck out at the Germans in a series of
counterattacks. The interpreter's unit, the 24th Infantry
Division, had suffered many of these for the past week.
In this positional warfare, it was the chief duty of the
wiretapping squad to preclude surprise attacks by
eavesdropping on enemy talk that would give hints of
Russian intentions. To this end, members of the squad
had, after the suspension of the first systematic German
offensive against Sevastopol, when Russian counterattacks
might be expected, crawled to the Russian lines on 7
January and left there a loop of wire. One of three such
loops, it did not actually connect to the enemy wires, but
detected the return speech currents in the earth, like the
Arendt apparatus of World War I. It thus picked up, not
the distinct conversations of a single line, but some 20
telephone stations with consequent cross-talk and hum.
For the first week, it produced general intelligence on
enemy equipment and supplies, replacements and their
instructions, observations, morale, losses, and battle
measures. Twice it enabled the Germans to save their
scouts, once from enemy gunfire, once from encirclement,
by alerting them that the Russians had spotted the
patrols.
On 15 January the Russians began a week-long series
of attacks aimed particularly at winning observation
posts that would overlook the German rear, as
well as tying down and weakening German forces.
The Germ~n wiretappers provided clues that helped alert
This was taken from a chapter of Mr. Kahn's new book,
Hitler's Oracles. Used with permission of the author.
their division to Russian activities. They heard a speaker
asking "Where am I going to get some schnapps?" and
another promising to fire "very, very much" on a bunker.
On 21 January, the attacks started early in the morning.
The battles flamed in close combat along the main trench
line, and at one point the Russians broke through, only to
be quickly thrown back. During the early afternoon a
pause set in. The infantrymen waited uncertainly, not
knowing whether they were through fighting for the day
or whether the Russians would suddenly rain shells upon
them and follow with a renewed onslaught.
At 4 p.m. the interpreter heard Russian Post 21 calling
all company commanders to the telephone. After some
indistinct expressions, he heard the commander at Post 21
say clearly:
"Forty-five minutes left till chen."
Ten minutes later, a Russian telephone speaker asked
another:
"Usina! When are we supposed to begin again?"
To which the reply came:
"In 35 minutes."
The interpreter reported this to the divisional G2, who
correctly interpreted it as another attack. The troops were
alerted. As the Russians assembled their companies, the
artillery of the 24th, of the neighboring 50th Infantry
Division, and of the corps brought them under fire.
When they finally attacked in battalion strength, only
weak leading elements even reached the main German
lines, and the infantry repulsed them with their light
weapons. The Russians returned to the attack in several
uncoordinated pushes but were repeatedly thrown back.
Ar 6:45 they finally gave up, returning to their original
positions and leaving the Germans firmly in control of
their main lines.
The German Staff declared the next day: "Wiretap
reconnaissance again achieved important results in the
enemy attacks on 21 January, creating the basis for their
successful warding off. In defense, wiretap reconnaissance
is of controlling importance, which is widely recognized
by the combat troops."
UNCLASSIFIED 3

UNCLASSIFIED
Unlike political circles, the military welcomed
communications intelligence. In fact, in the field it
became the most important source of enemy intelligence.
In only one place does the Treaty of Versaillesmention
intelligence agencies. Its table listing German infantry
division strengths allowed the signal detachment to
include an intercept section. The German army did not
use the men for the low-level work that had been
intended, but assigned them instead to the army's 12
major radio stations. In 1925, with Germany increasingly
departing from the Versailles restrictions, the army set up
six posts specifically for interception. Each had three or
four receivers served around the clock by about 20
radiomen, The difficulty of following foreign maneuver
traffic from these fixed locations led in 1928 to the
erection of mobile direction finders near the borders, and
two years later to the creation of mobile interception units
which evolved into mobile intercept companies. Directing
this work was first the Cipher Center and then the new
agency organized by about 1939 in the army command:
the Main Intercept Post.
The intercept organization was part of the signal corps,
which was headed by General Erich Fellgiebel. He was
subordinated in wartime to the chief of the general staff;
he served simultaneously as head of armed-forces
communications, making him also the superior officer of
OKW/Chi, A bespectacled, kindly, well-liked officer in
his early fifties, divorced and remarried, a former chiefof
the Cipher Center, Fellgiebel won high praise from the
OKW chief, Keitel: "In his field a pronounced leader
type with broad vision, a gi ft for organization, full
energy, , , satisfied even the most unexpected and
difficult requirements." But Keitel added that Fellgiebel
inclined to an "unconsidered mania of criticism" towards
Naziism. And indeed FellgiebeJ participated in the 1944
attempt to kill Hitler. His hesitancy in sealing off
communications to the Fuhrer headquarters after the
bomb went off contributed to the failure of the plot, for
which the conspirators, including himself, paid with their
lives. He was succeeded in both his army and armed
forces offices by General Albert Pr aun, 49, a short,
pleasant, extremely capable signal officer who had also
led an infantry division and who was, Chief of Staff
Guderian wrote, a "good National Socialist."
These two men, especially FellgiebeJ. presided over the
remarkable expansion of German army communications
intelligence in World War II. It provides a classic case
history of how an intelligence organization develops in
response to the requirements of intelligence consumers
and its success in satisfying them.
At the stan of the war, army communications
intelligence operated on four levels: the Main Intercept
Post at Zossen, 10 fixed intercept posts that passed their
information to Zossen and to the army groups, 7 mobile
intercept companies attached to armies, and intercept
platoons within the divisions. But communications
intelligence scored only minor successes during the Polish
campaign. Fellgiebel traced this in part to the distance of
the Main Intercept Post from the action. But bringing
control closer to the front implied a dispersal of control,
and all the lessons of radio reconnaissance taught that
strong centralization was essential for success. Fellgiebel
compromised. He created commanders of intercept troops
to handle communications intelligence for each of the
three army groups getting ready to attack France.
This organization worked well on the higher levels in
the French and Russian campaigns. But the tactical results
continued to be poor, So in 1942 Fellgiebel centralized
this work. He pulled men out of the intercept platoons of
the divisions, which were left with only a squad, and
assembled them in short-range communications
reconnaissance companies. He gave one to each army
headquarters. The company scattered its platoons
throughout the army's area: two platoons for message
interception, two for short-range direction finding, five
for wiretapping. To rationalize the terminology,
Fellgiebel renamed the armies' intercept companies "longrange
communications reconnaissance companies," the
Main Intercept Post the" Main Post for Communications
Reconnaissance," and the commanders of intercept troops
"commanders of communication reconnaissance."
Each army then had a short-range company and either
a long-range company or a fixed intercept post. Again
centralization promised improvement. On 15 December
1943, FellgiebeI united each army's organs into a
communications reconnaissance batallion. The 17 that
existed were in turn grouped into 8 regiments for
communications reconnaissance, each under a commander
of communications reconnaissance at army group or
theater command, Finally, early in 1944, the only field
level that did not have its own agency, corps, set up small,
10-man units to evaluate the material that came in from
the divisions and from any nearby platoons of the shortrange
companies.
In the fall of 1944, Praun carried all this to a logical
conclusion. At the very peak, he created a general of
communications reconnaissance to assure cooperation
among the various units and to improve personnel and
equipment. Genera! Fritz Boetzel, a man of some charm
and broad cultural interests and a one-time head of the
Cipher Center, was named to the post. This gave
communications intelligence its sixth and final level and
completed its evolution into a highly articulated
organizaron that effectively served all commands and
4 UNCLASSIFIED

UNCLASSIFIED
delivered the most valuable enemy intelligence that came
to German army generals during World War II.
The work of many of the officers in many of these
posts can be illustrated by the daily routine of a young
lieutenant, who despite his low rank became in effect the
commander of Communications Reconnaissance 2, the
regiment that served Army Group Center. He was Fritz
Neeb, a stubby young Viennese who had been interested
in cryptology as a teenager. He read everything he could
find on it in the Austrian National Library and cracked
the cryptograms that friends made up for him. Through
some blunder on the part of the German army, he was
actually put into the kind of work 'for which he was best
suited. He served in communications in the Polish and
French campaigns and the first part of the Russian-early
in which, while a member of the 137th Communications
Batallion, he captured 130 Russians 20 miles behind
their lines. One day his major met an old friend, the
colonel commanding the Army Group Center
communications reconnaissance regiment. The colonel
told the major of some of his problems, and the major
responded that he had a young lieutenant who had
resolved those same problems within his battalion. Three
days later Neeb was at the regiment's headquarters.
Codenamed HEINRICH EAST, it was located on rwo
floors of a former Russian secret police building in
Smolensk. Neeb was at first just one of several able
evaluators but as first one and then another of the officers
departed, and eventually the chief himself was
transferred, Neeb became virtually the commander of
HEINRICH EAST, with its 400 men, and made the
daily reports to the army group G 2 Colonel Rudolf
Christian Baron von Gersdorff.
His day began when he got up about 11 p.m., after the
most important reports from the subordinate companies
came in. He looked through these, gave assignments as to
how they were to be handled, and from about 3 to 5 a.m.
assembled the daily report, either by dictating it or by
simply assembling the rewritten drafts of the subordinate
companies' reports. Between 5 and 7 a.m. these reports
were teletyped to the Main Post for Communications
Reconnaissance and to the subordinate armies'
communications reconnaissance companies. Five or six
copies went to the G 2 and other officers of his own army
group. If no immediate questions came in, Neeb could
then go to sleep about 6 or 6: 30; otherwise, 7: 30. He
awoke again around noon, ate in the officer's mess, put
out a short so-called "advance report" of four or five
pages with the most important new information, and then
prepared for the daily G 2 situation conference in
Gersdorffs office. These began at 4 p.m. and sometimes
lasted three hours. Here the leaders of the various organs
of specialized reconnaissance submitted their results and
compared them. Often the discussions were very lively.
Neeb had to advance communications intelligence
entirely on its own, without recourse to any other source.
At about 6 or 6: 30, or sometimes 7, he went home,
grabbed a bite to eat, and went to bed to try to get some
sleep.
Sometimes instead of sleeping Neeb went to or gave
instructional lectures, for he realized that for him and
others on the same schedule it often didn't pay to try to
sleep a few hours in the early evening. He also prepared
tests for potential crypanalysts and evaluators, and during
the course of time tested more than 1,500 persons to try
to cover his personnel needs. Twice he gave information
out over the telephone in his sleep. He had no recollection
of it when he awoke, but was told ofit-and found to his
relief that the information had been correct. Thereafter
he had a wire recorder attached to his telephone.
The production of communications intelligence began
with an assignment from an intelligence officer.
Sometimes this simply called for general information,
sometimes for specifics on, for example, artillery or
armored formations. The communications reconnaissance
commander disposed his units to obtain the raw material
he needed to fulfill the assignment. In the west, Colonel
Maximilian Baron von Oer, the higher commander of
communications reconnaissance (called "higher" because
he had two regiments under him), sought simply to get as
much information about the Anglo-American forces as
possible. Before the invasion, his Communications
Reconnaissance Battalion 12 concentrated on radio traffic
in and with the United States. After the invasion, he
shifted ten receivers of its Fixed Intercept Post 3 at
Euskirchen to cover Great Britain. He divided British
army traffic between Fixed Intercept Post 2 in Port
Marly, which listened from 4,500 to 7,500 kilocycles
with a search up to 10,000, and Post 12 in Louveciennes,
which listened from 3,000 to 4,500 with a search from
100 to 3,000 kilocycles. Within each post or company,
the commander might further divide up these bands into
subbands and assign one to each of his approximately 36
receivers. The monitoring radioman would tune slowly up
and down, sometimes listening to two frequencies at once,
until he heard a transmission. He notified the directionfinding
team. If they told him the transmitter was outside
of the interception area, he continued his patrolling of the
other. If it were within the area, he continued to listen.
He observed the tone of the transmitter and the "fist" of
the radioman-his way of sending, which is as distinctive
as handwriting. These alone could often identify a
particular radioman, whose moves from one place to
another-and by implication the moves of his
unit-could therefore be followed. The monitoring
radioman also noted other details, such as the wave length
UNCLASSIFIED 5

UNCLASSIFIED
of the transmission, the calling station's sign, the called
station's sign, and cipher recognition groups as he wrote
down the intercept.
These intercepts poured out of the radio room, where
the monitors sat with their headphones on, into an
evaluation center. Each command level had such a center,
corresponding in size co the volume and complexity of its
work. The centers divided into subsections for traffic
evaluation, direction-finding evaluation, contents
evaluation, and final evaluation. The raw data could often
reveal much. Long wave lengths often meant higher
staffs; short waves, corps and division staffs; ultrashort
waves, armor. Since not every unit held every cipher, the
cipher recognition groups helped define communications
nets and so, by implication, command organizations.
Supplementing this was direction-finding. Monitors in
widely separated locations turned the movable antennas
of their specialized radio sets until they heard an enemy
transmitter at its quietest. A calculation indicated in
which direction it was. They reported this direction to the
direction-finding evaluation subseccion. It plotted, on a
map, the bearings given by several monitors. Where these
lines crossed marked the location of the enemy
transmitter.
The traffic evaluacors then listed on cards all stations
using a certain frequency, all stations called by a
particular call sign, and all known locations of the
different stations. They diagramed these relationships and
saw what patterns emerged. One station addresses
messages to many others, which seldom
intercommunicate; direction finding shows it further to
the rear. The evaluators deduce that it represents a higher
echelon commanding the others. A higher volume of
traffic on one circuit may portend an attack, a withdrawal,
a relief, perhaps only a disciplinary problem, but almost
certainly something. The evaluacors followed the
movements of the stations. Often they were extremely
acute. Once the Russians sent an armored army toward
Stalingrad while leaving some of the army's radiomen in
its old location to give the impression that it was still
there. But on the march, one of the radiomen who had
gone along inadvertently transmitted. The Germans
picked up his transmission, recognized him, and
concluded that the armored force was moving south,
probably toward Stalingrad.
Valuable as these inferences from the traffic patterns
were, they could seldom provide the insights that the
actual contents of the enemy messages could. Many of
these were unenciphered. Indeed, at the lowest level, such
cleartext radio or wire intercepts provided about 95
percent of communications intelligence. Sometimes they
shocked with their revelations of enemy attitudes. In
Russia on 17 February 1944, the 17th Panzer Division
overheard a conversation on 1,960 kilocycles at 10:30
a.m.:
Rokot:
Tochka:
Rokot:
Tochka:
Rokot:
Thirty minutes ago my patrol came out of Oktyabr
and reported that no one is there. It found only our
own wounded.
Why was it shot into! You're dogs, bastards, traitors.
The battery commander fired without an order.
Arrest him and shoot him with his own pistol.
Acknowledged.
Other times the cleartext messages provided helpful
background information. In May 1943, radio
reconnaissance of a landing practice of the Royal Marines
near Southampton shed light on amphibious tactics. The
Germans learned that the Marine division landed on a
width of 10 miles in the morning hours, attacking with
three brigades in the forward lines. Despite strong
"enemy" counterattacks, by 5 p.m. it had reached the line
Totton-Ringwood, two-thirds of the way to its objective
12 miles inland. Most rarely, c1earcext intercepts revealed
actual enemy intentions. In November of 1944, the 26th
Panzer Division in Iealy intercepted an order for a
bombing mission naming in clear the village that
headquartered the neighboring 278th Infantry Division.
It sent a warning, and the 278th suffered only minor
casualties. Similar cases in Russia led a commander of
communications reconnaissance to declare in mid-1943:
"The monitoring of the radio voice traffic (short-range
intelligence coverage) brings valuable results."
Wiretapping produced a lower volume of intercepts
than radio, and seldom overheard anything but front-line
conversations of limited concern. The German troops
crawled from their own to the enemy trenches and either
tapped directly into the enemy telephone lines or set out
loops that picked up ground currents, which were then
amplified.
During the Russian campaign, the wire reconnaissance
team of the 72nd Infantry Division, advancing into the
Crimea, hooked into the wires on the permanent
telephone poles along the main road. Through these
during a German attack, the team heard the Russian
defenders being told that it was absolutely necessary to
hold a certain position and that reinforcements were on
the way. The conversation included details about the
Russian guns and their locations. All this enabled the
Germans co rush up their own reinforcements and to take
the position.
Clear text messages like these nearly always
outnumbered cryptograms. In September of 1944, for
example, the commander of co rnrnu n i ca t i o ns
reconnaissance 7, in Italy, picked up 22,254 clearcexts
and 14,373 cryptograms. This preponderance stemmed
from the enormous number of short local messages within
6 UNCLASSIFIED

UNCLASSIFIED
a division. At the higher echelons, where orders live
longer and therefore allow more time for encipherrnent,
the proportion of cryptograms increased, until at the top,
practically all messages were enciphered. They were
obviously of far greater importance than those in clear.
To get to their contents, the Germans had to crack open
their cryptographic armor. As the enemy improved his
cryptographic protection during the war and extended it
to more classes of messages, the German army's
cryptanalytic establishment grew to keep pace.
The Main Intercept Post had only a handful of
cryptanalysts at the beginning of the war-five for all
Britain, for example. By 1942, it had 200, divided into
country sections and such service sections as those for
Hollerith machine processing and for archives. It attacked
not only the enemy high command systems but also those
unsolvable by field echelons, which worked on the
simpler cryptosystems of the enemy units on their level
opposite them.
At first the Germans had relatively good success with
the Russian codes. The solved messages, said the
cryptanalysts of Army Group North in 1944, "contain
operational combat reports, statements about assembly
areas, command posts, loss and replacement reports,
reports about chain of command and positions prepared
for the attack (e.g., messages of the 122nd Armored
Brigade on 14 and 17 February)." These results came
from only a small proportion of the intercepts. In the
thirteen months from 1 May 1943 to 31 May 1944,
Army Group North intercepted 46,342 Russian
cryptograms. It solved 13,312, or less than one in four.
Its commander of communications reconnaissance
explained why:
"It is only infrequently possible to get enough
identically enciphered messages from the same net to be
able to solve the current systems." Later he adduced
additional reasons:"... a growing complication in the
systems used by the enemy ... a greater care in
enciphering ... (avoidance of identical addresses and
signatures; names and phrases with characteristic endings
and patterns, which must be given in code form in
individual letters or syJlables, were either enciphered
abbreviated or were inserted in cleartext)."
In other words, as Russian code construction and
discipline improved, German cryptanalytic success
declined. Whereas from May to August 1943 the Army
Group North code breakers always solved more than 34
percent of all intercepts, from January to May 1944, with
even greater monthly volume, they never solved more
than 33 percent. These almost never included the toplevel
command systems. It was the same for the western
Allies. In general, the Germans failed to read the
messages moving in the higher command nets.
The cryptanalysts passed their solutions CO the contents
evaluators, who passed their conclusions in turn to the
final evaluators. They combined these conclusions with
those of the traffic evaluators. Often their analysis could
precipitate precious observations. The evaluators of
Intercept Company 3.jN.7 Ord company of
Communications (Nachrichten) Battalion 7) did so for
the 11th Army in March of 1942.
In its drive to conquer the Crimea, the 11th Army had
split the Russian forces on that peninsula. It had penned
some in Sevasropol in the west; it had not yet swept away
those in the eastern portion, an elongated peninsula
ending in the city of Kerch. These Russian eastern forces,
controlled by the Crimean Front, continued to assemble
troops for a counteroffensive. The intercept company
concentrated much of its effort at determining the
composition of these forces, since this would help the
Germans know how many of their own troops they might
have to use to repel the Russian attacks in their rear.
This was the situation when, at 7: 16 a.m. on 13
March, the company intercepted a message to an
unknown radio station with call sign SOTD. It was
addressed "To the chief of communications of the 44th
Army." This indicated pretty clearly that SOTO was the
44th Army, and since company's records showed that
direction-finding had located SOTO transmitting from
near Kerch, the company could report a few hours later to
the intelligence officer of the 11th Army, .. 44th
Army definitely on the Kerch Peninsula." It was one
more element in his picture of the enemy.
Though these chains of hypotheses might seem to have
led to freq uent error, constant observations corrected
wild reasoning and kept the results close to the facts. A
few days after the intercept comr.any identified the 44th
Army, it assigned radio station OPWCH {O the air staff
of the enemy's 51st Army on the similar basis of a message
address. But the following day, it recognized that the net
to which OPWCH belonged was in fact identical to a net
of the 44th Army .. according to the net construction,
frequency notifications, and statements of the
monitoring radiomen." OPWCH was therefore a station
of the 44th Army, the company concluded, and had
probably merely accepted the message for forwarding
tothe51stArmy.
Through such detailed and often wearisome activity,
German radio intelligence units contributed enormously
UNCLASSIFIED 7

UNCLASSIFIED
to German tactical and operational intelligence. In these
low and middle echelons, it warned of enemy attacks,
provided solid information on enemy order of battle and
enemy weaknesses, and saw through both radio silence
and radio deceptions.
In Russia, for example, the Main Post for
Communications Reconnaissance issued a report each day
listing all enemy troop units recognized or confirmed
through communications intelligence. A typical such
report ran 14 pages for Soviet army units, 2 for partisan
forces, and 2 for air units. From the south to the north of
the long Russian front, it dealt with the major commands,
as far down as divisions. "5th Guards Army. Directionfinding
for the army command from 24 August [1944J
indicate the area southeast of Staszow [Poland].
According to a message of 7: 30 a.m. 25 August it is
changing its location," read one entry. Another entry,
based on a Moscow broadcast praising heroic units, listed
a score of divisions, their commanders, their location, and
their subordination. This top-secret report, produced in
37 copies, went to Foreign Armies East, where it joined
other sources in creating a picture of the Soviet forces
opposite the German.
In France in 1944, the higher commander of
communications reconnaissance likewise achieved good
accuracy in determining American order of battle.
Between D-Day and 25 June, it recognized the presence
of the U.S. 1st Army, 4 corps, and 15 divisions or pares of
divisions. Under the VIIIth Corps, for example, it
correctly listed the lOlst and 82nd Airborne Divisions
and parts of the 90th Infantry Division. Much of this
information later appeared in the order of battle reports
of the G2 of the commander-in-chief west. Toward the
end of June 1944, the breaking of a logistical code used
by the senior officer, Ferry Control, in the area of the
British 2nd Army in Normandy gave the Germans exact
figures on the personnel and e

UNCLASSIFIED
But communications intelligence did not invariably
enable the Germans to win victories. Sometimes its
information. though correct when delivered, was falsified
by enemy plan changes that it did not detect. For
example, in 1943, the commander of communications
reconnaissance of Army Group North reported: "An
intended Russian attack on Staraya Russa was recognized
on 25 June, which was to begin at 2300 hours 25 June
and in which 6 armored battalions, among others, were to
take part. The attack, however, was not carried out,
probably because of the unfavorable weather conditions."
Communications intelligence was also often nullified
by any of the host of nonintelligence factors that
determine success and failure in battle. On 9 August
1944, the Main Post for Communications
Reconnaissance disclosed in its report that "11th Guard
Army gets order to improve clothing, get new underwear.
all airplanes to be overhauled and prepared for flight,
provisions to be improved and three hot meals a day
served." The next day, the Germans, who were preparing
a relief operation, learned through radio intelligence that
two of the 11th Guard Army divisions were ordered to be
ready to go into action against enemy attacks by 5 p.m.
When the Germans began their drive on the l oth, the
11th Guard Army responded with a counterthrust, just as
predicted. But this forewarning did not enable the
Germans to stop the Russians, one of whose platoons
carried the ground war. for the first time, onto the soil of
the Reich.
And sometimes communications intelligence simply
failed. The evidence on which it rested was
ethereal-peepings in rad iornen' s earphones-and could
be suppressed or faked. Occasionally the Germans turned
radio silence against its users: the 7th Army G 2 declared
in France in November 1944 that radio silence suggested
Allied attack preparations. But in North Africa, the
British concealed a division very close to the front by
shutting off their radios for several weeks. Radio silence
also preserved surprise for many Allied landings in Sicily
and Italy. Radio deceptions sought to fool the Germans.
The Russians tried this every few weeks, but the Germans
always seemed to see through them. On the other hand,
the British successfully covered the transfer of three
armored divisions from one point in the line to another
during the Normandy battles through radio deception.
Perhaps the most common failure was simply
rnisevaluation. In November 1940, the chief of the
general staff, Halder, thought that an intercepted message
referring to a transfer of headquarters might mean that
the English were about to occupy all of Ireland to get the
western harbors. He was all wrong. Before Leningrad in
June of 1943, the commander of communications
reconnaissance in Army Group North reported: "The
[Russian] 8th Army had only a little radio traffic in the
early days of May and soon afterward complete radio
silence ensued .... Together with the radio silence of the
8th Army, the irregular and opaque traffic of the 2nd
Shock Army and the change in location of the command
post of the Leningrad Front ... , it is concluded that a
Russian attack of considerable magnitude is imminent."
It never came.
But the many successes counteracted these occasional
failures. Moreover, communications intelligence
produced great quantities of information about the
existence, locations, and movements of enemy
formations-the basic enemy order-of-battle intelligence
that says so much about enemy capabilities and intentions.
Consequently, by 1943, commanders in the field, who in
1939 had mistrusted communications
intelligence-particularly when it came, not from the
contents of messages, but from inferences based on
traffic volume and routing-came to look upon it as their
best source of intelligence. The G2 of the XXXXth
Panzer Corps noted that through the "outstanding"
communications intelligence in February 1943 the corps
"always knew almost exactly the enemy situation,
location and strength. This knowledge contributed
considerably to the complete annihilation of the Popoff
armored army." During Normandy, the G2's in the west
drew about 60 percent of their information from radio
intelligence, 40 percent from all other sources combined.
The chief of staff of the western theater called it "the
most important means for clarifying the enemy picture."
A head of Foreign Armies West called it "the darling of
all intelligence men;" the head of Foreign Armies East,
Gehlen, listed it as the most important of his sources.
And Halder flatly declared it to be "the most copious and
the best source of intelligence."
The glowing testimonials that many high-ranking
officers gave to army communications intelligence
referred only to tactical and operational results. For on
the strategic level, German communications intelligence
failed utterly. In contrast to the Allies, who could read all
levels of German cryptosystems up to those enshrouding
the command messages of the Fiihrer himself, the
Germans-though they sometimes read diplomatic
messages of Roosevelt and Churchill-never cracked the
high- and top-level military ciphers of the Allies. Thus
unlike the Allies, who often knew German plans for the
overall direction of the war, the Germans never knew the
Allies'. Probes of high-level Allied messages showed that
they could not be solved analytically. Testing them all
statistical]y for a possible cipher clerk's error that might
9 UNCLASSIFIED

UNCLASSIFIED
have permitted the solution of a dozen or so would have
taken too many cryptanalysts away from work that,
though lower in echelon, was more certain of results. So
the Germans did not seek to crack these high-level
messages, and after a while they even gave up intercepting
them. This was their unacknowledged admission ofdefeat
in the most vital sector of the secret war.
David Kahn is the leading authority on cryptology in
America, outside of Government Service. He has served
as president of the American Cryptogram Association and
the New York Cipher Society. A member of the faculty of
New York University, he is the author of technical and
popular articles on cryptology and of The Codebreakers
(1967) and the recently published Hitler's Spies.
10 UNCLASSIFIED

NSA Cryptologic Spectrum Article:
German Intercept Successes Early in
World War II
Fall 1978 - Vol. 8, No. 4

Wilhelm Flicke
UNCLASSIFIED
German Intercept Successes
Early in World War II
A German cryptologic officer's account of intercept In the West
The campaign in the West in the summer of 1940
appears to many people to be the master stroke of a
military genius. Even when we take into account the
German superiority in numbers and materiel and
appraise adequately the spirit of the German troops,
many things still remain inexplicable - in particular
the swift drive through the northern continuation of
the Maginot Line. On the basis of what I was able to
learn, I shall attempt to throw a few side lights on
this campaign, without pretending to be able to explain
everything.
I have already reported on the situation in the
intercept service. Conditions for successful intercept
work were as favorable as one could desire in France,
Holland, and Belgium.
From intercept traffic the French assembly and the
Belgian and Dutch frontier defenses could be recognized
so clearly both in respect to organization and
geographical distribution that the information was
fully adequate for making German dispositions. It was
a pleasure for the German command to be able to
enter the enemy's troop dispositions on its own situation
maps on the basis of the results of the intercept
service. In the present case, however, this did not
suffice. Before the war the great question was: how
good will the mighty defense system of the Maginot
Line be? Will it be possible to break through quickly
or will a war of position on a large scale develop here?
Will modern heavy artillery be able to crack these
defenses? Who could answer these questions?
Earlier we reported how Poland and Czechoslovakia
were thoroughly reconnoitered by the German espionage
service. In France there was no such degree of
success although the German intelligence service did
receive current reports and single notices. France had
no extensive German minority and conditions were less
From War Secrets in the Ether, translated by Ray W. Pettengill,
NSA, 1959.
favorable. Nevertheless, in the summer of 1939 the
German Secret Service succeeded in pulling off something
which absolutely made up for the previous years.
In August it was possible to get a photograph of a
French map showing all forts, barriers, obstacles,
communications routes and communications points of
the Maginot Line and of its extension to the coast.
This showed how imperfectly the French had developed
their system of defense along the Belgian frontier and
one did not need to study the map long in order to put
his finger on the weakest point in this system of
defense. This map was reproduced in Germany and
was the basis for planning the campaign in France.
In order to drive at this weak point in the French
system of defense, it was necessary to advance through
Holland and Belgium. Consequently, this move was
decided upon in Germany without hesitation. The
prospect of overrunning the French line swiftly was
too inviting, and it was impossible for the French to
build up this weak point within a few months to match
the strength of the Maginot Line proper.
The campaign against Poland was followed by a
period of calm. Only in the air and at sea did some
minor engagements take place, which no one regarded
very seriously. People were already beginning to crack
jokes about the "phony war." Many thought there
would be no serious conflict and that France and
England were in a state of war merely "to save face"
with respect to Poland. Peace would surely come in
the spring.
The monitoring of French and English traffic, however,
did not indicate that people in those countries
were concerned with "saving face." War production
was under way; they were arming for battle, though
only for a defensive struggle. The whole system of land
defense for France since 1919 had been based on the
invincibility of the Maginot Line, while England was
convinced that economic measures directed against
UNCLASSIFIED 25

UNCLASSIFIED
Germany would not fail. Anyhow, one could not count
on a conciliatory attitude in either France or England.
On 'l:7 January was broadcast Churchill's speech in
which he said: "Hitler has already lost his best
opportunity."
On 9 April the German people were suprised by the
information that "German troops have undertaken the
protection of Denmark and Norway." The National
Socialist Government tried, naturally, to throw all
blame on the English and Norwegians. Of course no
mention was made of the fact that the invasion might
not have been successful, if the intercept service of
the German Navy had not ascertained the position of
the British naval forces and calculated the time so
that no suprises need be feared from that quarter.
Despite heroic resistance, all Norway was occupied
within four weeks during which the German intercept
service played a notable role against both land and
naval forces. At Narvik, both the British and Norwegians
used radio very incautiously. The course of
British ships could be followed perfectly at all times.
Several Norwegian units were encircled and captured
because of their incautious use of radio, and the
capture of Bergen with its war stores was possible only
because of frivolous use of radio.
Of course the Germans sometimes made mistakes,
too, and the British followed German ship movements.
Simultaneous with increase in military radio traffic
at the beginning of these operations was the enormous
increase in diplomatic and press traffic. It was interesting
to see how the German advance against the two
northern countries affected neutral lands. While the
German press tried to characterize the whole action
as a "British Crime" against which the entire press of
the world was clamoring indignantly and while German
papers were printing quotations from foreign papers,
which had been paid for with German money, intercepts
from foreign countries gave a very different
picture. British action against Norway had been
started only after Germany's intention had become
known to England at the last moment. Consequently
it was not England but Germany that had attacked,
and this unjustified attack in defiance of all international
law lost Germany the respect of the world and
laid the groundwork for her defeat.
On 9 May one of the leading German newspapers
carried the headline: "Stupid British Diversionary
Maneuver." The content was to the effect that the
discovery by Germany of ostensible British plans had
produced such an impression in England that they
were resorting to diversionary maneuvers; news was
being spread abroad that Holland was sorely threatened
by Germany. There was a false report that two
German armies were moving toward Holland, but of
course that was nonsense, an old wives' tale of the
Ministry of Lies in London. But the next day at nine
o'clock Doctor Goebbels delivered a long talk on the
German invasion of Holland, Belgium, and Luxenbourg.
The war in the West had begun.
The attempt to attribute the blame for the outbreak
of hostilities to the Dutch and Belgians was ridiculous.
From everything that could be observed by monitoring
their traffic, it was clear that both countries did
everything possible to maintain neutrality. On 14 May
the Dutch army gave up the hopeless struggle and a
break was made in the extended Maginot Line at
Sedan. On 16 May came a break through the Maginot
Line on a front of 100 kilometers. On 17 May German
troops entered Brussels. Soon Hitler's threat: "We will
put them in a panic which will spread!" was made
good.
This creation of panic was carried on by all modern
technical means. Leaflets were dropped by the
hundreds of thousands and served to spread the wildest
rumors. Agents deposited by parachute behind the
enemy front cut in on the telephone wires, called up
all sorts of government offices, gave false instructions
to civilian offices and troop units, and by reports of
panic caused a chaotic flight on the part of the civilian
population, which resulted in a hopeless blocking of
the highways. Captured radio stations were likewise
put into operation and issued alarming reports. With
events moving so rapidly, the French command had
no possibility of effectively counteracting these activities;
moreover, the French did not catch on to these
methods until too late. In several cases, whole divisions
were forced in this fashion to surrender. A number of
German agents equipped with small shortwave radio
had been deposited behind the French front and were
working from there with excellent success. These
people watched everything that went on and reported
each of their observations immediately to one of the
three control stations by which their work was directed.
For the first time in history a combat instrumentality
was employed here which in the later years
of this war was to give it its special character and
which was to be turned in catastrophic fashion against
Germany.
On 3 June the frightful slaughter known in history
as the "Battle of Flanders" ended with the capitulation
of the Belgian army and the encirclement and annihilation
of British and French forces. These troops
fought bravely but succumbed to superior force. The
name Dunkirk became for the Germans the symbol of
a decisive victory over England and for the British
the symbol of a most successful evacuation, carried
26 UNCLASSIFIED

out with the aid of the fleet. Both were right ­
everything depends on the point of view.
Once again there came a period of tense expectation.
What would happen? Would the Germans turn south
and attack the French divisions on the Aisne and the
Somme, or would they follow British troops across the
Channel? The word "invasion" began to spook around.
The German High Command diligently spread the
news that it was preparing to invade at once. In any
case the fate of France was virtually sealed. This
seemed to be a suitable time for Italy to enter the
war. Pressure was put on Mussolini. A feverish exchange
of telegrams between Berlin and Rome began.
And finally it happened. On 10 June 1940, from the
balcony of the Palazzo Venezia, Mussolini proclaimed
to the Italian people and to the world Italy's entry
into the war on the side of Germany. This was
speculating on a cheap victory, on sharing the spoils
after France had been completely subdued and England
had pulled out of the war, as it was expected to
do.
But even in this seemingly so favorable situation,
the true attitude of a large part of the Italian Officer
Corps, in particular General Staff Officers, was and
remained adverse both to the war and to Germany. A
not inconsiderable group of officers was outright anti­
German in sympathy to such a degree that this could
be clearly recognized from intercepted Italian traffic.
We shall have occasion to speak of this later. For the
moment, however, the chances seemed to favor the
two Axis Powers and for the moment this outweighed
everything else.
The battle along the Aisne and the Somme began
and in a few days the French army was split into four
groups. On 15 June, German troops crossed the Loire.
On 18 June Hitler and Mussolini met in Munich to
discuss the terms of an armistice. On 22 June, the
armistice was concluded in the Forest of Compiegne;
the French fleet remained in French harbors.
France was beaten. Hopelessly beaten in an astoundingly
short time. How could this country, protected by
the most modern line of fortification and with its
strong army, be conquered so easily? For one thing
the Germans, contrary to French expectation, had not
hesitated to attack two neutral and almost defenseless
countries, Holland and Belgium, and thus to reach the
French frontier where it was least well protected.
Moreover at the beginning of the war France was
distinctly inferior in materiel. There was lack of
planes, armoured tanks and other war equipment.
Despite all warnings, including repeated reports to the
Deuxieme Bureau regarding German armament, those
in control refused to believe there was any serious
danger.
UNCLASSIFIED
When the campaign in the West began, the French
greatly underestimated German strength, while espionage
had revealed to the Germans the weak points in
the French line of defense. Another unexpected factor
was the systematic spreading of panic. In a very short
time, millions of French and Belgians were in flight,
blocking roads and bridges so that French troops and
supplies could not get through. On top of all that,
there was the German radio intercept service. Most of
the French army cryptographic systems and two systems
of the French Foreign Office were known to the
German cryptanalytic service. Countless messages with
highly important content could be read. Moreover,
diplomatic representatives of various countries were
transmitting by radio important information and were
doing this in systems already solved in Germany. From
a purely military angle, the system of French army
traffic resulted in revealing to the German Intercept
Service in a very short time the relation between the
higher and medium units. The organization of the
French front was known at all times. No movement
and no dislocation remained concealed from the Germans.
The French Air Force was most incautious in
its use of radio and the ground stations gave countless
clues. The picture was the same as that observed
during French maneuvers from 1930 to 1939.
The map of the line of fortifications, the intercept
service, the cryptanalytic service, the creation of
panic, the blocking of highways, air superiority, and
superiority of numbers and materiel on the German
side, coupled with an ineffective intelligence service
on the French side - nothing more was needed to
gain a crushing victory in the West.
The campaign in the West had ended. Throughout
Germany bells pealed and flags fluttered. People were
convinced that victory in the West meant the end of
the war; now it was up to the diplomats to find a way
to bring about peace. It was incredible that England,
the last remaining antagonist, would dare to continue
the war. Goebbels organized a mighty reception for
Hitler when the latter returned from the front; the
rumor was spread that America had intervened and
England would make peace. Plans for demobilization
were worked out and a few people were discharged
from the armed forces.
But although people were convinced in Germany
that England would now try to get out of the war,
longboats, light sailing vessels, motorboats and other
craft began moving northward on special vehicles; they
were to carry German troops across the Channel and
few people doubted that this enterprise would shortly
be crowned by success. Yet week after week passed
and nothing happened. On the contrary, the German
intercept service was obliged to report again and again
UNCLASSIFIED 27

UNCLASSIFIED
that England had no thought of submission. Moreover,
voices from America also had to be taken seriously.
While the public was thus forced to settle back and
wait for the invasion which Hitler said was coming, it
was remarkable that all preparations for invasion were
carried on in the open instead of being carefully
camouflaged as usual. Details which normally would
have been strictly secret could be heard everywhere,
until one almost had the impression that the invasion
was nothing but a bluff.
Interception of English traffic, however, gave the
impression that the British were counting on an
attempted landing. Their air reconnaissance of points
where the Germans were concentrating small boats
became intensive and the assemblies were bombed
constantly.
Meanwhile the air war against England began. It
was supposed to break the will of the people to resist,
but it soon brought two disappointments: first, the
British fighter defense proved far stronger than expected;
second, the effect of the bombs was by no
means as great as had been expected. Furthermore,
German aircraft losses increased rather than decreased
- some days a hundred or more machines were lost.
Careful monitoring of all radio traffic between Great
Britain and the U.S. A. showed no indication of any
letup in England's will to resist. Week by week the
United States was growing closer and closer to Great
Britain. Unmistakably there was a resolve to put an
end to the conquest of one country after another by
National Socialism. The attitude of the U.S. A. was
expressed in a speech in Philadelphia on 18 August by
Mr. Bullitt, former ambassador to France.
Since the air war was not achieving its purpose, the
German Government proclaimed in August a "total
blockade of England." This step was aimed primarily
at the U.S.A., but its effect was like pouring oil on a
fire. It really betokened German weakness rather than
strength.
While the German press printed long-winded articles
on the effect of German air attacks on London, only
small type was available on 10 September for the news
that the House of Representatives had on the day
before accepted the Bill for Compulsory Military
Service. The question was no longer, "Will the U.S.A.
fight?" but, "When?"
Supposedly, the invasion was to take place during
the night of 15-16 September 1940, but the English
fighter defense was still too strong, the Navy was still
intact, and German preparations were too inadequate.
Only a few of the 1,000 large transport gliders called
for had been completed. The espionage service had
almost completely failed to function; in particular the
establishment of a network of radio agents had never
gotten beyond very modest beginnings. The intercept
service provided virtually no information regarding the
military situation in the British Isles.
Of course the decisive factor was Hitler himself. He
did not seriously believe it would be necessary to
invade by force; he expected England to make peace
and Ribbentrop held the same view. Not until four
weeks after the conclusion of the campaign in the
West did Hitler realize that this assumption was not
correct. Hitler could pursue a goal with great obstinacy
but he was an easily influenced, emotional character
and now he shifted suddenly and ordered the General
Staff (or at least part of it) to make plans for a
Russian campaign which had never been mentioned
before. He thought that England would change its
attitude immediately, if Germany should attack the
Soviet Union. Hess entertained the same opinion.
Points of difference between England and the Soviet
Union were well known, likewise Churchill's aversion
to Bolshevism. If the English attitude took the course
they expected, then invasion was superfluous.
It is true that there was a dilemma; Hitler must
say one thing to the Germans and another to the
English. It was necessary to explain to the German
people why the invasion did not come off: first there
was fog, then there were storms, then it was said
spring was the only proper time, and then when at
Headquarters the idea had long since been dropped,
"preparations for the invasion" were carried on in an
ostentatious manner. The British were to get the
impression that the invasion was imminent and the
bombing attacks continued, although their intensity
decreased. The main activity was confined to threats.
Amid this tense expectation there was concluded
with great pomp on 26 September 1940 the so-called
Three Power Pact between Germany, Italy, and Japan.
This act was purely theatrical. It was the first confession
of the fact that from now on the whole threat of
an invasion was merely a bluff, because if there were
an invasion and England were defeated, then there
would be no need of exerting pressure on England in
the Far East. The fact that this step was taken proved
that the German Government had no illusion regarding
the invasion, even if it should be carried out. Actually
the plan had already been given up. It was interesting
to see how they reached the same conclusion in
England; this was revealed by the mass of intercepted
diplomatic messages of other governments, Poland in
particular.
The Polish Government had fled to London and was
in close contact there with all organs of the British
Government and with the British armed forces. The
English on their part esteemed this cooperation since
the Polish element all over Europe gave a unique basis
28 UNCLASSIFIED

for the organization of a large scale spy network for
the English secret service. The reverse of the medal
lay in the fact that the Polish Government in London
talked too much out of school in its exchange of
telegrams.
The cryptographic systems of the Polish Government
in Exile for the most part had been solved in Germany.
Consequently, insight was obtained into the thinking
and the plans of influential English offices. It could be
seen that the British took the invasion seriously for
only a short time. In any case, they were ready to
accept it and were resolved, in case it succeeded, to
continue the struggle from overseas. The fleet was to
go to America and the struggle would be organized
anew from there. Africa was to constitute the starting
point for the attack on the Axis Powers. There were
similar revelations in the intercepted traffic of diplomats
representing other nations.
The German plan aimed, by threatening British
possessions in the Far East, to force Britain to change
her military dispositions. The idea appeared very
clever and in those days Ribbentrop was considered in
Germany a very competent and clever diplomat. However,
he had neglected one important factor: should
Japan try to disturb the balance of power in the Far
East, this would inevitably arouse opposition in the
U. S. A., and relations between the two countries were
already tense due to the conflict in China. When the
Japanese raised 'this objection, Ribbentrop assured
UNCLASSIFIED
them that the U. S. A would not be in a position to
employ its whole strength against Japan because
Germany would, in case of conflict, declare war on the
U. S. A.; this would mean for both the U. S. A. and
Great Britain a splitting up of forces, and the Americans
would be too weak to threaten Japan seriously.
At that moment, what Ribbentrop said was valid,
but one factor was omitted: in September 1940 we
had from intercepted traffic a fair picture of war
production in the U. S. A. with production estimates
for the two ensuing years. Compared with German
production these figures were enormous. Hitler and
Ribbentrop said these figures were pure pipe dreams.
What induced them to take such an attitude is not
known to me. The figures were not based on propaganda
speeches but were carefully compiled from
authentic sources. On this occasion Hitler displayed a
characteristic trait; he would believe only what accorded
with his ideas, everything else he rejected
abruptly.
Wilhelm Flicke worked in German cryptologic
organizations, as an analyst and administrator,
from World War I through World War
II. The rights to his Kriegsgeheimnisse in
Aetber, which covers both wars, was purchased
by the U.S. Government shortly after World
War II.
UNCLASSIFIED 29

NSA Cryptologic Spectrum Article:
Critical Analysis of German Operational
Intelligence Part II
Winter 1980 - Vol. 10, No. 1

UNCLASSIFIED
Critical Analysis of
German Operational Intelligence
Part II
Sources of Intelligence
The study of sources and types of intelligence
available to the Germans shows clearly how the inherent
weaknesses' of their intelligence system extended
to their detailed work. The insufficient importance
they attributed to intelligence meant that all its
branches suffered from shortage of personnel and
equipment; and, although in some fields there was an
approach to German thoroughness, in the main the
lack of attention to detail was surprising.
The interrogation of prisoners of war, which they
regarded as one of their most fruitful sources of
information, is a good example. In the beginning of
the war, their need for detailed and comprehensive
interrogation was small; but even later, a standard
OKH questionnaire was still being used and at no time
was much initiative shown on the part of interrogators.
Only later, in the Russian campaign, did it become
obvious to the Germans that their system was not
nearly flexible enough and that more individual attention
had to be paid to the problem of exhaustive
interrogations. Even so, it seems clear that Allied
interrogation methods, employing more and better
interrogators and producing competent work at all
levels down to battalion, were probably far superior to
anything the Germans ever knew.
The same holds true for work on captured documents.
The Germans realized the value of document
From German Operational Intelligence. Military Intelligence
Division, War Department, Washington, D.C., 1946.
work, and many German field orders stress the importance
of the capture, preservation, and quick evaluation
of enemy documents; but they paid scant attention
to adequate training of personnel, and no
outstanding work seems to have been done. During the
second half of the war, the amount of captured
documents in German hands decreased, owing to the
nature of their defensive warfare, and the opportunity
for good document work became fewer.
That the Germans were capable of good detailed
work is shown by their practice in the Internment
Center for Captured Air Force Personnel at Oberursel,
where all Allied air crews were first interrogated. The
German specialists here realized the value of combined
document and interrogation work, and devised an
excellent system of analysis. In order to identify the
units of their prisoners - a matter of the highest
importance to the Germans so as to analyze the
steadily increasing size of Allied air fleets - they
went so far as keeping card files on the types of ration
cards issued to the Americans, or the type of photographs
used for their identification papers, etc. Generally
speaking, so exhaustive a study was unknown in
the Army.
A major contributory cause of the weakness of
German intelligence was their loss, toward the end of
the war of an important source of intelligence - air
reconnaissance. The failure of the German Air Force
to stay in the air during the last two years of the war,
meant an almost paralyzing loss of eye-sight to the
German Army. The Germans expended much ingenuity
in the development of other sources of intelligence,
but for the long-range exploration of enemy intentions,
16 UNCLASSIFIED

UNCLASSIFIED
the loss of air reconnaissance, both visual and photographic,
remained a severe handicap. There was practically
no air reconnaissance over England prior to D­
day, with great consequent advantages to the Allies at
a time when their preparations and concentrations
could hardly have been concealed from the air.
This failure was a purely physical one, for the early
campaigns of the war, when the Germans had air
superiority, showed that they fully realized the value
of serial photographs as a source of intelligence in the
planning of tactical operations. In the planning of the
campaign in France, the field echelons were given
aerial photographs of the Maginot Line, both verticals
and obliques, in sufficient quantities for distribution
down to companies. This undoubtedly helped their
successful campaign against the line.
As the war progressed, there was a definite shift of
emphasis in photographic interpretation from tactical
to strategic considerations, i.e., to photographic reconnaissance
and interpretation of enemy air forces,
air fields (France), enemy navies, ports and shipments
(England), air fields and landing places for parachute
troops (Crete), roads and supply routes (Russia). Until
late 1942, photographic reconnaissance planes remained
under the commander of the air support
(Koluft), the officer who was responsible for supplying
photographic coverage to field units. After 1942, such
available planes were taken over by the Air Force and,
though theoretically they were to function as previously,
flight missions for photographic reconnaissance
were no longer automatic but had to be requested.
Not only did the quantity of necessary photographic
missions decrease, but the quality of photographic
reconnaissance also deteriorated rapidly when Allied
air strength forced photographic reconnaissance planes
to be equipped to fight and to be flown by men who
were primarily fighter pilots.
Along with the reorganization, useful experiments
which were in progress ceased altogether. Developments
in night photography, so important in Russia,
infra-red photography, and penetration of non-transparent
intermediaries were either curtailed or stopped
altogether. Technically trained civilian personnel (e.g.,
from the Hansa Luftbild Companyj were absorbed
elsewhere, and there was no one left who had either
the technical knowledge or the energy to pursue further
developments in this field. Because of lack of supervision,
the entire field of photogrammetry, with the
exception of rectification, was ignored. Finally, there
was no coordinating authority, nor anyone of sufficiently
high rank to sponsor air photographs at higher
headquarters. Such were the conditions on the higher
levels. It must be emphasized that, fundamentally,
the entire subject of photographic intelligence was left
in the hands of Air Force personnel. This meant that
the air liaison officer and his staff not only arranged
for the flying of the missions, but were responsible for
the developing, interpretation, and reproduction of
photographs as requested by the Army G-2, with
whom the air liaison worked closely. The implication
of this must be immediately apparent, for such cooperation
presented the problem of training Air Force
personnel in interpretation for use in ground force
operations.
That this was realized can be established by the
existence of a photographic intelligence school located
at Hildesheim. Significant is the fact that emphasis
was laid on studying photography, the technique of air
photography, and the handling of cameras; interpretation
was taught to a limited extent. It was only in
the officers' course that the subject of enemy Army
organization and tactics were stressed. Though advanced
courses were offered, specialists were developed
only through actual experience, and more in the
various practical aspects of photographic reconnaissance
than in interpretation itself.
Over-all policy and direction for the training of
interpreters were lacking. Although there were other
schools of limited duration instituted by the higher
air echelons of the various theaters, the need for
courses in ground tactics, enemy Army organization,
etc., was never fully realized.
With this thought in mind, the limitations of
photographic interpreters attached to army (the lowest
level at which interpretation was carried out) must be
realized. The tactical problems of one division, the
need for minute study and interpretation of its sector
as seen from verticals (scale 1:10,000), obliques, and
from semi-oblique stereographic pairs, could not be
taken care of at army.
To illustrate this important point, let us consider
the problem of a division. Since a mission could be
flown by neither division nor corps, the request was
passed on through the chief intelligence officer at
army, who stated his request to the air intelligence
officer indicating the limits by coordinates. The latter
prepared the mission and coordinated it with the
reconnaissance section which carried it out. The interpretation
was done by the photographic reproduction
section (Stabia), which returned the interpreted photographs
with annotations to the air intelligence officer
responsible for their sorting, filing, and distribution.
Through intelligence channels, four or five copies were
forwarded to the division in question which distributed
the photographs to the various commands. Interpretation
at army obviously could not be so efficient as at
UNCLASSIFIED 17

UNCLASSIFIED
the division concerned, where so much more was known
of the terrain and the local problems; and it was often
necessary to refer back a questionable interpretation
to the photographic reproduction section at army
(Stabia) to clear it up. Systematic and continuous
coverage, so necessary for a proper interpretation, was
seldom possible, in view of the many limitations, as
well as the lengthy front of an army and, correspondingly,
the sector of a division.
On the eastern front, the Germans attributed the
shortcomings of their photographic intelligence to the
skillful camouflage of the Russians, their excellent
road discipline, and their ability to transport great
numbers of troops at night. Perhaps a more accurate
explanation was the lack of planes and equipment in
the German Army, their poor technique, and the
inadequacy of their personnel, both in quantity and
training. Finally, there was a lack of supervision and
control in the filling of the requirements of ground
force field echelons when the interpretation was done
by Air Force personnel. Technically, German air
reconnaissance, as long as it could be practiced, was
sound; interpretation, even in the first two campaigns
of the war, was never really well-developed or organized.
The loss of air reconnaissance was an incentive to
the Germans to develop their methods of radio intercept
work, and signal intelligence later became important
on all fronts. In the West, it accounted for
approximately 60 per cent of all intelligence received.
With the development of signal intercept, although
it made no essential difference to the attitude of the
General Staff, there could be found the beginnings of
a higher prestige for intelligence work. Good intercept
work, producing, as it did, almost 90 per cent reliable
information, was invaluable for helping the intelligence
officer to sell himself; and the efforts expanded by the
Germans in this field, in training specialists and
equipping field units with intercept teams, reflect the
greater value they attached to it.
It is true to say that this was the only field of
intelligence in which the Germans came near to an
adequate personnel and technical solution. They
trained and prepared a sufficient number of specialists,
from operators and technicians to mathematicians and
linguists; the amount of equipment at their disposal
was limited by the shortage of labor and materials
and does not seem to have been very plentiful, but, on
the whole, was sufficient to meet the steady expansion
and improvement of the service.
Another important factor in their success was the
close cooperation built up between the intercept agencies
and the G-2s of the various command echelons.
This was insured by locating the command posts of
the intercept and evaluation units at or near unit
headquarters. In addition - and this was probably
the key to their ultimate success - the Germans
realized at an early date, through practical experience,
that the greatest gains could be achieved only through
a physical dispersal of the actual intercept stations
coupled with a strictly centralized direction and evaluation
of the results. They learned that in this field
a correct picture could be obtained only by assembling
all the intercepted messages at higher headquarters
and by disseminating intelligence from the top down,
rather than from lower echelons up. This avoided the
danger of overestimating the value of a single message
and insured that it received its proper place in the
over-all picture.
Throughout this work, the Germans appear to have
concentrated on the aspects from which they could
gain quick and operationally useful results, and to
have limited the over-all effort. They made little
attempt at intensive work on high-grade ciphers, which
offered great resistance to the cryptographers but
stressed the rapid exploitation of low-grade codes and
messages in the clear, and the development of means
for rapid dissemination of the results. They did not
achieve the mass of intelligence produced by the Allied
intercept organizations: but, even at the cost of
security, they did at least equal the Allies in the
production of results of tactical value to the lower
levels.
A good example of this was their work on Allied air
liaison nets. Messages from ground forces calling for
air support, were often evaluated sufficiently to enable
the troops to be warned, though the actual targets
mentioned were in a code which the Germans were
unable to break. In the West, for example, a broadcast
system was established and put at the disposal of the
Chief Intelligence Office at Western Theater Command,
with receivers at all division, corps, army, and
army group headquarters. (This was a system often
considered by the Allies but always turned down for
security reasons.) There can be no doubt that by a
procedure such as this the Germans succeeded in
disseminating the results of intercept more rapidly
than the Allies, but they fell short of the over-all
results of Allied intercept, and impaired their effort
by poor security.
The Germans distinguished between long-range and
short-range reconnaissance through agents. Although
both types were under the Abwehr and after 1944
under the Military Office of the National Security
Office (i.e., under the 8S), there were important
differences.
Long-range secret intelligence was handled by static
headquarters, which were usually in Germany proper
18 UNCLASSIFIED

UNCLASSIFIED
or at least far behind the actual front lines. They sent
agents who were not employed on front-line activities
through neutral countries, or by parachute, far into
the rear of enemy territory. It has not been possible
to check the German claim that these agents were
reasonably successful, especially in the West. Coverage
of English invasion bases prior to D-day, for example,
was claimed to be adequate, and, until fairly late in
the western campaign, there were no surprises so far
as order of battle was concerned.
Prior to their attack in 1941, the knowledge about
Russia which the Germans possessed was scanty.
Although it is said that the German attache in Moscow
repeatedly informed his superiors of the strength of
the Soviet Union, the Germans either disbelieved his
reports or did not have enough information on that
point from other secret sources. Intelligence on the
whole had greater difficulties to overcome in Russian
than in the West, and the Germans themselves admit
that most of the material available before the inception
of the campaign was of doubtful value.
In the short-range secret intelligence the Germans
obtained their greatest successes in Russia and in
Italy, and were least successful in the West. This type
of work was in the hands of Abwehr units and subunits,
which, after the reorganization in 1944, were renamed
intelligence reconnaissance units and subunits (FAKs,
FATs). They were mobile units attached to army
groups and army. For operational intelligence they
were important in two ways: FAKs I (or Abwehr I)
sent agents through the enemy front lines, FAKs ill
(or Abwehr ill) were engaged in counterespionage and
the apprehension of Allied agents behind the German
lines. The counterespionage work of FAKs ill, which
seems to have been most successful in the East in the
appreciation of the Russian employment of agents and
the knowledge of the various missions assigned to
them, formed one of the most important bases upon
which the operational intentions of the enemy could
be estimated. It was complemented by signal intelligence.
FAKs ill furnished a consolidated report on the
activities of Russian agents every ten days. These
reports were evaluated by the sections dealing with
partisan matters, where a map was kept showing when
and where the agent was detected or apprehended
and, if known, by whom he was sent out. Army
information concerning the agent's mission was included
in a legend to the map. It was found, by
experience, that the entries, as they increased in
density in certain sectors of the front, indicated very
clearly where the Russians were planning to engage in
large-scale operations. It was also found that on those
sectors of the front where a large number of agents
who had been given their missions directly by the
General Staff of the Red Army were being employed,
a clear picture of impending main efforts could be
obtained. In this way, the defensive use of secret
intelligence on the eastern front was particularly
valuable to operational intelligence. The offensive use
of German espionage behind the Russian front lines
also seems to have shown fairly good results. It was
estimated that only 20 percent of the messages received
by German agents were of value, but that those
messages were extremely useful for operational intelligence
and well worth the effort and expense. The
same seems to be true of the Italian theater, where by
and large, the Germans were able to obtain good
results through agents and counterintelligence work.
In the West, however, the picture was different. FAKs
ill were successful up to a point, but their reports on
apprehended Allied agents did not form the basis for
any operational intelligence comparable to that carried
on in the East. And as far as FAKa I, i.e., active
espionage through and behind Allied lines, were concerned,
German efforts were a dismal failure. In view
of the successes achieved on other fronts, this may
sound surprising but close analysis reveals several
reasons for it.
Until D-day in June 1944 there was no front line
and the FAKs could not engage in active espionage by
which they might have gained experience and developed
the required machinery. In Russia and Italy, the
necessary organization was developed over a period of
years, whereas in France the Germans were faced with
a new situation for which they could not be completely
prepared.
The Abwehr was reorganized on 1 June 1944, and
was transformed into the military office under SS
leadership. Direction of espionage came into the hands
of party fanatics, who were little more than dilettantes
in this field. A few days after D-day, the confusion
that reorganization caused in the higher echelons
hindered the study of current procedures and the
carrying out of the necessary improvements. In the
East and in Italy, experience was gained throughout
the campaigns. The espionage machinery was in existence
in June 1944, and the changeover amounted to
little more than a change of name, higher administration,
and command channels. This only slightly encumbered
current work.
In the Russian and Italian theaters of operations,
the work of German agents was helped by the confused
political and ethological situation. This facilitated
both recruiting and employment of agents. In Russia,
although the bulk of the population was wholeheartedly
on the side of the Red Army, a considerable number
UNCLASSIFIED 19

UNCLASSIFIED
of Ukrainians, White Russians, and Cossacks, were to
some extent pro-German. This made penetration of
enemy organizations by agents comparatively easy.
Only SS stupidity and unwillingness to arrive at a
political compromise with some of the anti-Soviet
groups in Russia and Poland ruined this fertile ground
for German espionage. In the West, on the other hand,
the Germans were faced by solid blocks of hostile
populations. England, favored by the insular character
of the country, was a particularly difficult problem for
agents. By 1944, France also had become almost
solidly united against the Germans as a result of the
short-sighted manner in which the Germans treated
the French.
Directing secret service work is, perhaps more than
any other kind of intelligence work, largely a question
of personalities. Many agents do not work directly for
a cause, but are mercenaries working for the officer
who hired them. Often they do not even realize what
cause they are working for. This requires a great deal
of personal skill and knowledge of psychology on the
part of the directing officer. In addition he must have
detailed and accurate knowledge of the enemy, of local
conditions and habits, and of tactical situations. He
must work relentlessly and have a love for anonymity.
Altogether the German character, so easily given to
illusions, romantic speculations, and spectacular deeds
does not lend itself too well to secret work. In that
sense, the Germans obviously did not have the right
personalities available when the invasion started. It is
quite typical that, in order to reinforce their organization
in the West, the Germans brought, from an
army group in the East, the experienced commander
of a FAK, an officer who had never worked in the
West, but who knew France. It is reported that this
officer, although at first quite unfamiliar with local
conditions, achieved more in two weeks than his
predecessor had attained in six months.
In the East, there was no continuous front line, and
the employment of agents, their infiltration through
the enemy lines, and their return were comparatively
easy. In Italy, the long coastal stretches on both sides
of the country favored the employment of agents, since
they could enter and return from enemy occupied
territory by water around either end of the front. In
the West, however, more or less continuous front lines
existed - at least during the static phase of the war
- that hampered the regularity of such movements.
The Allied employment of agents in the West gave
the Germans little indication of Allied intentions. In
the East, -communications behind the front lines were
exceedingly poor as compared to the West, and the
Russians, in order to gain important data about the
enemy for their next operations, had to send their
agents directly into the region in which they were
interested. In the West, there was no technical difficulty
in sending agents to Holland with missions
covering anything between the Ruhr and the French
Alps. The place of capture, therefore, meant very
little unless the exact mission of the man became
known, so that intelligence obtained by counterespionage
in the West could be used for operational purposes
only in an extremely indirect manner.
Concerning the organization of the secret service,
one other point needs emphasis - the dual chain of
command of the intelligence reconnaissance units. For
formation, direction, and administration they were
first under the Abwehr and later under the Military
Office of the National Security Office. The tactical
employment of these units, however, was a function of
the chief intelligence officer at army group and army
level. He never personally directed agents, and almost
never saw an agent himself. He could give orders and
designate objectives to the commanding officer of the
FAK who, in turn, had to take the steps needed to
achieve the results desired by the chief intelligence
officer. To this extent - i.e., in having an agent
organization over which the local commander had little
or no control - the Germans suffered from the same
disadvantages as the Allies.
Channels
Distrust of the specialist was the chief factor in the
strict limitations set by German Army orders to
intelligence channels. In practice there was more
freedom than appeared. The chief fault, as far as can
be ascertained, was that, while the intelligence channel
was efficient in the forwarding of information (Foreign
Armies in Berlin was informed of new identifications
in a matter of hours), the channel was not so effective
as a means of exchanging ideas. The extent to which
the G-2 of a field unit could discuss with his superior
G-2s the day's information, and thereby outline the
enemy situation with them, was severely limited by
the fact that he was required to submit his ideas to
his G-3 or his chief of staff. The influence of these
operations officers in intelligence matters was, by
Allied standards, far too great; for, instead of having
the differences in appreciation straightened out over
the telephone between G-2s, the chief of staff and
even the commander, came into such discussions much
too often. The result of such a procedure was that the
intelligence picture at the various echelons frequently
differed. This had two negative results. First, it did
not help to raise the prestige of the intelligence officer
20 UNCLASSIFIED

UNCLASSIFIED
in the eyes of the rest of the staff. Second, it lessened
the contact between intelligence officers of different
echelons. Many divisions, for example, instead of
placing reliance on the enemy division history folders
produced for them by higher authority (a good feature
of German intelligence), preferred to compile and keep
up their own. The 65th Division in Italy, for example,
built up its own division folder, relying largely on the
results of its own interrogations.
This extent of self-reliance often caused a lack of
harmony in the solutions of the day-to-day problems
in interrogation and appreciation which repeatedly
plagued division, corps, and army intelligence officers.
Foreign Armies
There is little doubt that of the two agencies
Foreign Armies East and Foreign Armies West - the
one dealing with the eastern theater of war was the
more valuable and efficient. After its initial grave
errors in its judgment of Russian military strength
and over-all war potential, the work of Branch Foreign
Armies East improved steadily. There are several
reasons for this superiority over Foreign Armies West.
After the initial failure of the Germans to bring the
campaign in the East to a quick and successful
conclusion, General Halder, then chief of the Army
General Staff, realized that intelligence methods had
to be radically altered and improved. His choice for
Chief of Foreign Armies East, Brigadier General
Gehlen, was excellent, and it was due to the latter's
personality and drive that the branch attained a
degree of efficiency which, because of the lack of such
leadership, Foreign Armies West never equaled.
Branch Foreign Armies East profited by the fact
that the direction of its theater of war was always
under the OKH and the Army General Staff, and that
its mission was simply to be the intelligence agency
for the OKH. This facilitated the coordination of all
intelligence efforts. Foreign Armies West, on the other
hand, suffered from an increasing influence of the
OKW and its political leaders in the so-called "OKW
Theaters", i. e., the Balkans and Italy, and later the
West. The branch was, therefore, under the dual
control of the OKW and the Army General Staff,
which encumbered the coordination of work and the
speedy solution of problems.
Although certain intelligence sections, notably those
dealing with the Balkans, the United States, and the
Pacific, were shifted back and forth several times
between Foreign Armies East and West, Foreign Armies
East was, on the whole, allowed to concentrate its
efforts on Russia alone. This meant that the branch
could be organized on the basis of a functional rather
than a geographical division of work, so that Section
I dealt with operational intelligence, Section II with
long-range research, statistical data, manpower, etc.,
Section ill with translation and propaganda work,
Section IV with all matters pertaining to Sweden,
Section V with map and photographic reproduction,
and Section VI with personnel administration. To a
great extent, this avoided duplication. Foreign Armies
West, on the other hand, dealt with a number of
enemy armies and was organized according to countries,
not theaters. The duplication resulting from this
was realized by the Germans, and they created the
office of an executive officer whose section was responsible
for the intelligence of the Italian theater as a
whole. For the western theater, separate sections dealt
with the ·British, French, and American Armies and
with other Allied forces, a separation which was not
suited to the production of an harmonious intelligence
picture.
From 1941 until the end of the war, there was a
continuous campaign and a gigantic front in the East.
This enabled German intelligence to gain experience
constantly and to develop and improve its methods of
collecting and evaluating information. Although, in
1941, the Germans knew very little about Russia and
the Red Army, they were able in the course of the war
to establish a fairly adequate and reliable Russian
order of battle. That the result of their labors was
neither well used by the High Command nor much
believed by Hitler, was not Gehlen'a fa_ult. _In._~he
West, the Germans gained considerable insight into
the organization of the British Army through and
after Dunkirk. For the next four years, the German
and Allied armies were in fighting contact only in
North Africa and Italy, which hampered the continuous
collection of intelligence by the Germans. They
were able slowly to pick up knowledge about the new
British and French Armies and the US Army in North
Africa, Sicily, and Italy. It may be true, as the
Germans claim, that on 6 June 1944, the new situation
did not confront Foreign Armies West with any major
surprise in order of battle, but it still remains very
probable that the branch did not have too extensive
a knowledge of Allied intentions.
The center of gravity of German operations was in
the East. The Russian campaign absorbed most of
Germany's manpower and material. Accordingly, Foreign
Armies East had a much greater staff at its
disposal and was in a position to do more thorough
work and to publish more detailed reports. As far as
can be ascertained, Foreign Armies West never em-
UNCLASSIFIED 21

UNCLASSIFIED
ployed more than 100 people, whereas Foreign Armies
East had, at its peak, several times that many.
Foreign Armies West, not equipped to deal with
economic matters, gave these only secondary treatment,
and relied, to all practical purposes,on the
efforts and results of the Field Economic Office (Feldwirtschaftsamt)
in the OKW. Foreign Armies East
paid increasing attention to the questions of the
Russian industrial and armament potential, and organized
Subsection IT for that purpose. Foreign Armies
East even joined efforts with the Field Economics
Office by taking as chief of Subsection II an officer
who was also a specialist on Russia in the Field
Economic Office, so that the work of both agencies
was properly coordinated, and each office could utilize
directly the facilities of the other for carrying out its
work.
Through Gehlen's outstanding personality, Branch
Foreign Armies East gained direct influence over
agencies whose efficient functioning was important to
its success. The tactical employment of agents came
directly under the branch, which was able to direct
short-range secret intelligence in accordance with its
day-to-day needs. In the West, there was no such
simple chain of command, and the intellignece reconnaissance
units did not do nearly so well.
Such were the main reasons for the noticeable
difference in efficiency between Foreign Armies East
and West. Because of outstanding leadership, Foreign
Armies East received all the support and cooperation
it needed in order to increase its intelligence effort
according to the needs of the German Army. Foreign
Armies West, lacking such support, remained a small
agency too busy with the day-to-day technical details
of work to develop into the large central intelligence
agency which the Germans needed for their great fight
in the West. In neither case, however, while the
Army's and the High Command's attitude toward
intelligence remained what it was, could these agencies
carry out their mission adequately.
Conclusion
The results of this study are largely negative. It
shows that the German approach to intelligence was
a faulty one: insufficient attention was given to the
subject as a whole, its importance was generally
underrated, and the intelligence officer was rarely able
to attain the prestige necessary for his job. For the
first three years of the war, this had but little adverse
effect on operations, but later the very success at arms
which the Germans had enjoyed served only to increase
their neglect of intelligence, so that, as the tide
turned, they were unable to estimate correctly the
extent of allied superiority. It would be untrue to infer
from this that German intelligence was bad. Perhaps
it would be more precise to call it "mediocre", and to
say that its disadvantages were largely offset by the
high military efficiency of the Germany Army as a
whole.
Because there is little that the Allied intelligence
services can learn from the Germans, no attempt has
been made in this study to collect every possible detail
of German methods and their results. These have been
merely outlined and only those aspects from which a
lesson could be learned have been considered and
emphasized. Some of the different methods used by
the Germans point a moral, as in the case of their
concentration on signal intelligence, their emphasis on
low rather than high-grade ciphers, and their disregard
for security in the dissemination of results. In other
procedures, they stressed detail to an extent which we
might well follow. Apart from these points, this general
discussion of German methods can have at least the
negative value to Allied intelligence of lessons in
weaknesses.
22 UNCLASSIFIED

NATIONAL SECURITY AGENCY
JOURNAL ARTICLES
WORLD WAR II
GERMAN CRYPTOLOGY
BACM RESEARCH
HTTP://WWW.PAPERLESSARCHIVES.COM