Military Communications and Information Technology: A Trusted ...

476 Military Communications and Information Technology...
In the article we present the way of modification of management process
which allows to improve the efficiency of ECDMS.
II. Characteristics of special data protection systems
and cryptographic data management systems
in our considerations we take into account the special systems of data protection.
The term “special systems” is quite general. For the purpose of our article we
assume term “special systems” means systems processing classified information,
that is information particularly important and sensitive. The priority is the security
of their data, sometimes with cost of processing speed or ease of use. Below
we will discuss the main features of the special systems, which directly determine
the requirements for ECDMS.
1. Communication between any two elements of the system (users, devices)
is protected by encryption with a unique key, called the session key. Session
can be a single conversation. It can also be defined by the unit of time or
the size of transmitted data.
2. Information must be protected not only currently but also a long time
after use. The more sensitive information the longer period of protection
is required. Implemented cryptographic mechanisms must therefore be
strong enough to ensure the security now and in the future.
3. The conclusion above applies also to the protocol of the session key agreement.
In many solutions the key is agreed using the Diffie-Hellman protocol.
It can be considered sufficiently secure today, but there is no guarantee that
it will be quite secure in the future. For this reason, such key agreement
protocols can not be used in special systems.
4. Not all connections between system’s users are allowed e.g. in the army,
where every person on any command level should be provided with communication
with their immediate superiors, subordinates and people with
the same level.
5. Development of the system that is adding new users (devices) must be
strictly controlled.
Taking above requirements into account the following principles of cryptographic
data management can be specified:
– session keys, instead of agreeing, should be derived from the base key;
– base keys (relations keys) should be different for each pair of communicating
devices;
– establishing who with who can communicate in secret mode must be possible;
the set of established relations determines the configuration of communication
system;
– relations key are being prepared for a fixed period, called the period
of validity; after that period, they should be replaced by new keys; periodic