A Key Tree Merge Algorithm in Multi-privileged Groups

Many group key management schemes designed for hierarchical access control have been put forward recently. Some of these schemes use the integrated key graph to provide multiple levels of access control. However, most of these schemes focused on the efficiency of group key establishment and rekeying in centralized group key management schemes and didn´t indicate how to generate the key graph. In this paper, we presented a Multiple Key tree Merge (MKM) algorithm to generate the optimal key graph and improve the group key establishment and rekeying efficiency of contributory group key agreement schemes. Efficiency evaluation indicates that an approximately 30% reduction in computation overhead is achieved compared with that of the MG scheme.