Research On Re-keying Technologies For Secure Multicast Based On Logical Key Hierarchy

Re-keying is a major challenge to the group key management of large-scale multicast network. On the background of multicast with large and dynamic group users, we research re-keying schemes based on LKH in the centralized network, aimed to reduce the storage, computation and traffic of re-keying. The following results are achieved:A new taxonomy of group key management schemes is presented. The relationship between computation, storage and communication costs is analyzed in some key management schemes.The re-keying scheme based on secret sharing using LKH is brought forward. The server broadcasts messages when there is a member joining(or leaving) the group, so that the members can reconstruct the new group key using Shamir's secret sharing. In particular, this scheme can reduce the cost of computation and communication.A re-keying scheme that generates assistant key for group members based on identity is proposed, which can resist collusion attacks exist in EBS. When a user leaves the secure group, the scheme divides the other users into different sub-groups according to EBS and constructs a message using PE algorithm to reduce the storage and communication cost.Group re-keying scheme based on secret sharing is simulated in C++ and OPNET. Measurement results from experiments are presented. Compare with LKH schemes, the conclusion can be drawn that the group re-keying scheme based on secret sharing can improved performance in large dynamic multicast network.