An important problem for secure group communication is key distribution. Most of the centralized group key management schemes employ high rekeying cost. Here we introduce a novel approach for computation efficient rekeying for multicast key distribution. This approach reduces the rekeying cost by employing a hybrid group key management scheme (involving both centralized and contributory key management schemes). The group controller uses the MDS Codes, a class of error control codes, to distribute the multicast key dynamically. In order to avoid frequent rekeying as and when the user leaves, a novel approach is introduced where clients recompute the new group key with minimal computation. This approach ensures forward secrecy as well as backward secrecy and significantly reduces the rekeying cost and communication cost. This scheme well suits wireless applications where portable devices require low computation.

Keywords: Erasure decoding, Key Distribution,MDSCodes, Multicast.