Study And Design Of The Key Negotiation Protocol

At present the effective security scheme is the essential safeguard of data transmission in the open network. The only credence of access is secret-key in information security field. So how to provide the equal and effective group key for communication clients, especially for the most complex dynamic peer group becomes one of the topic study issues in nowadays. This thesis analyzes the available key establishment protocol which is suitable for group communication, and makes a deep research on the key negotiation protocol suitable for dynamic peer group. After the comprehensive comparison of every performance of the key negotiation protocol, the paper discusses the TTS, based on the tree structure and threshold theory. The TTS protocol has the advantage in computation in clients, so fit to common network condition. Adopting the threshold theory, it reduces the work of key-regeneration to the minimum when the group changes. The improved TTS key negotiation protocol, with small calculation cost, makes great progress in key verification, data source authentication and resist inners attack. The main works in this thesis is as follows: First, The thesis discusses the subject of q exponent primitive root in GF(p), which based on the faster algorithm of finding the primitive root. Then if p and q are large primes, it puts forward one faster algorithm which can find the q exponent primitive root in GF(p). Second, the paper improves the key negotiation protocol of TTS. The improved TTS agreement adopts high-efficient one-way Hash function and XOR operation, making it has such safe attributes as key verification, data source authentication and resists inners attack just at the cost of a slight increase in computation loads. Finally, the paper discusses and presents the thought, methods and the techniques on how to implement the improved TTS key negotiation protocol under VC++6.0, and solves some technique problems which can be found in implement of usual encryption software ,modular of large exponent arithmetic and the architecture of Shamir threshold.