Military Communications and Information Technology: A Trusted ...

Chapter 4: Information Assurance & Cyber Defence
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Disadvantages: Complicated and time consuming planning. Too large risk
of doing mistake (no necessary relations). For a large number of devices, error-free
planning is practically impossible.
Table II. Time of generation for different methods of planning
Number
of devices
Generation time
Case 1 Case 2 Case 3
100 1 h 22 min. 16 min. 1 h 22 min.
200 5, 5 h 1h 6 min 5,5 h
500 34 h 40 min. 7 h 15 h 53 min.
1000 5 days 8 h 27 h 36 min. 31 h 46 min
2000 23 days 4 days 15 h 2 days 15 h
5000 145 days 29 days 6 days 14 h
In conclusion, it should be noted that in extreme situations (large networks)
both methods in its pure form are not acceptable. Therefore, our solution is in some
sense a combination of both methods of planning.
VII. Adaptive method
General idea
This method is iterative. Iteration is single validity period. The method starts
from a network set up on each to each. The method is called adaptive, because
in subsequent iterations the network connections are modified in such a way, as to
adapt to the real needs for connections. The aim of this method is to obtain such a
set of cryptographic relations that will not require further modification (of course
apart from the modifications related to exceptional situations, such as the introduction
of new user).
Additional requirements
The method requires all active connections to be registered by devices
of the management system. Thanks to this, the planning subsystem will know
which relations are necessary. In a minimum variant, to record only the first call
within a relation is sufficient. For this purpose, an existing electronic distribution
channel can be used.
Initial conditions
Before the first iteration, the relations are established on each to each. Prior
to initiating the system there is not time regime yet, so it does not matter that