Hierarchical Data Processing Model and Complete Tree Key Management Mechanism

Logical key tree is an important issue for multicast key management. The degree of a tree and the algorithm which maintains the balance has great effect on the multicast key management. The paper makes an analysis on the key tree degree with using hierarchical data processing model. The complete quad tree is taken as the logical structure of the key management, and the rebuilding algorithm of a complete logical key tree is based on the idea of subtree movement so that the external cost which caused by the tree balancing can be reduced. This paper gives the designing idea, analyzes and devises the realization algorithms, and constructs a practical complete tree key management scheme. The analysis shows that this scheme is simple to realize and the cost is still low, being applicable to the situation where the group size is enormous and the changing of the group is frequent.