Abstract
Group key management is an important framework to secure group communications. To improve the performance of re-keying for group key management in large scale systems, logical hierarchical key was proposed. However, this approach does not consider the high re-keying cost of single user having multiple memberships. In this paper, we propose a membership oriented group key structure to optimize the re-keying of multiple membership users. Users in the systems are grouped into key-groups based on their memberships. Therefore, the re-keying operations for members of these groups can be combined without sacrificing forward secrecy. An analysis shows that the cost of re-keying operations in large scale multiple membership group key management can be improved with the proposed group key management.