ID-Based Hierarchical Key Graph Scheme in Multi-Privileged Group Communications

Many applications need the support of multi-privileged group communications, which use multiple data streams for members with various access privileges. We propose an ID-based hierarchical key graph scheme (IDHKGS) to manage multi- privileged group communications. The proposed scheme employs a key graph, on which each node is assigned a unique ID according to access relations between nodes. When a user joins/leaves a group or changes access privileges, other users in the group can deduce the new keys using one-way function by themselves according to the ID of joining/leaving/changing node on the graph. Compared with the existing MGKMS scheme, the proposed scheme can greatly reduce the rekeying overhead at the expense of a slightly larger storage overhead.