What is Forward Secrecy

In the real scenario, there is a large multicast group where nodes leave and join frequently, and also the number of nodes leaving and joining is also not proportionate. Hence, scalable rekeying process is an important issue that needs to be concerned for the secured group communication for dynamic groups. In basic rekeying scheme, which is based on the logical key hierarchy, the rekeying cost depends on the logarithm of the size of group for a join or depart request by the user. However, the memory efficiency of this group rekeying protocol (GREP) is a huge storage overhead over the system. The authors aim to provide a survey of various group key management schemes and then propose an efficient scalable solution based on linked LKH and the linked list data structure. Results have shown that the Linked LKH algorithm has a very low effective cost for rekeying the LKH as compared to the basic LKH algorithm (i.e., based on the number of new joined and departure requests).