Military Communications and Information Technology: A Trusted ...

Modern Usage of “Old” One-Time Pad
Mariusz Borowski, Marek Leśniewicz
Cryptology Division, Military Communication Institute, Zegrze, Poland,
{m.borowski, m.lesniewicz}@wil.waw.pl
Abstract: Top commands of the arm forces and some special military and government institutions
need perfect security for exchanging between them “TOP SECRET” information. Security of such
information is not limited by time. Only the one-time pad (perfect) cipher may be used to fulfill
the requirements. Realization of OTP cipher machines has changed for decades. Now capability
to hardware generation of binary random sequences with the potential output rate 100 Mbit/s
eliminates the restriction connected with availability of very long one-time keys. Continuously
generating the sequence (or one-time keys) with a bit rate 100 Mbit/s and its direct, lossless
recording to mass storage, the new hardware generator will be able to produce a little more
than 1 TB per day. OTP cipher machines have to be supported by a trusted data management
and couriering system.
Keywords: a one-time pad, a hardware random bit generator, entropy, randomness, Markow chains
I. Introduction
Diplomacy, military top commands and some special government agencies
need ever lasting absolute security and privacy. Interception of some
“TOP SECRET” plaintext by hostile state or organization can prove destructive
in two months as wall as in a hundred years. The requirement of the perfect cipher
usage is obvious for the institutions. It is important to recall that messages that
were encrypted in the 1950’s with ‘state of the art’ imperfect cipher machines, and
were kept archived by the adversary (which actually happened) are now generally
broken within a few seconds, minutes or some hours at the most. On the other hand
the messages that were sent 60 years ago with any realization of perfect ciphering
will stay unbreakable for ever if the keys have been destroyed.
Methods of realizating the perfect ciphering have changed by decades from
a pencil-and-paper version to a today’s PC computer system equipped with modern
software and provided other then confidentiality cryptographic services. It is
interesting that all the methods of realizating the perfect ciphering have the same
perfect security. Obviously perfect security is not for free. The perfect cipher requires
random keys as long as the plaintext, a data management system and a robust,
trusted key distribution system. Shown in chapter 4 the possibility for hardware