Military Communications and Information Technology: A Trusted ...

Chapter 4: Information Assurance & Cyber Defence
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keys exchange enhances security and it is an opportunity to reconfigure
the system;
– cryptographic relations are established according to the needs known
at the time of planning. In the moment keys comes to use or during
the validity period, these needs may change. It must be possible to
join the system devices that were not included in the communication
plan. For this purpose, sets of spare data are prepared. Spare data, after
uploading the devices, enable secret communication with all other devices:
working or spare;
– relations key should be supplied to the operation places in a reliable and
secure way before beginning of validity period, which they have been
prepared for, starts.
From above assumptions it follows that ECDMS performs the tasks associated
with planning, generation and distribution of cryptographic data. These processes
must be executed sequentially. Result of one stage constitutes the input for
the next stage. But the entire life cycle of the key includes the following key stages:
needs analysis, preparation, waiting for entry to use, activation, work: session
keys generation, deactivation, archiving or destruction. The process of preparing
the data can be presented in a transparent way on the timeline. The essential
points are: the beginning and end of the validity period (B and E), the beginning
and end of the data preparation process (Bp and Ep). The period between Bp and
B is designed to analyze the needs for secure communications to the next period.
The period between Ep and E is the reserved time required against unexpected
events. The shorter time of data preparation compared to the length of the validity
period, the management is more flexible. During validity period the following
steps are held simultaneously: data preparation for a future, using current data and
destruction of the previous keys.
III. Efficiency
Speed of processing can be regarded as the measure of efficiency. The speed
is connected with the time of the processing. Because of planning, generation
and distribution are realized sequentially the time of date preparation is equal to
total time of component processes. Time of planning depends on the planning
method one applies: “according to the needs” or “each to each”. Time of generation
depends on the number of established relations and the throughput of the source
of keys – usually hardware random generator. Time of distribution depends
on the kind of the distribution method, which can be courier (traditional) or
electronic one.
The kind of distribution is very essential for future conside-rations. In the case
of the courier distribution, cryptographic data are delivered to the points of exploitation
by persons (couriers). This process can last from several days to several