Non-Split Balancing Higher Order Tree for Multi-Privileged Groups
In group communication scenario, key management is important to preserve forward and backward secrecy. In order to achieve it keys need to be changed during user join/leave which is done by an operation called rekeying. In a centralized key management scheme, the server thereafter passes the new keys to the existing users who are affected via unicasts and multicasts. The number of unicasts and multicasts decide the rekeying cost. B-trees and NSBHO trees help to reduce the rekeying cost as compared to the binary trees. This paper discusses the use of these trees in multi-privileged environment providing the algorithms for user join/leave as well as rekeying algorithms in both the cases.