An Improved Contributory Key Agreement Protocol for Dynamic Peer Group
The Tree-based Group Diffie-Hellman Protocol is a fairly good key management scheme for dynamic peer group communications. Through analyzing TGDH protocol, the authors have found out that a deficiency exists with its mode of communication. A lot of redundant messages are used to complete group re-keying so that more communication bandwidth will be consumed in TGDH. This paper aims to solve the deficiency and improve TGDH through designing a preparatory algorithm of finding a Key Association Set. A new re-keying protocol is also designed by using the algorithm. Theoretical analysis shows that our protocol effectively decreases the communication and storage overload of TGDH, with the communication bandwidth descending from O(nlogn) to O(n) and the key storage descending from O(n) to O(logn). The simulation result also shows the improved protocol has a better communication performance.