A Method for Analysis and Design of Multicast Key Distribution
Hu Ru · 2005
All kinds of different methods based on rooted-tree multicast key distribution schemes make efforts to mini- mize the user key storage while providing efficient member deletion. In this paper, we show that the user key storage on rooted trees can be systematically studied using basic concepts from information theory, and the rooted-tree-based multicast key distribution problem can be posed as an optimization problem. In particular, we show that the entropy of member deletion statistics can quantifies the optimal value of the average number of keys to be assigned to a member. We then demonstrate the key distribution on rooted trees with an example of a key distribution scheme that attains opti- mality but fails to prevent user collusion.