Group Key Management Using Proxy Re-encryption for Dynamic Networks

Decentralized group key management mechanisms offer beneficial solutions to enhance the scalability and reliability of a secure multicast framework by dividing the whole group into subgroups. However, many of the previous decentralized solutions require the trust key distribution center, or don´t exploit the broadcast nature of wireless communication. In the study, a novel group key management scheme is proposed, which employs decentralized group membership, doesn´t relay on the trust center, and makes use of the wireless broadcast nature to efficiently accommodate dynamic group changes. The main contributions are:(1) we extend a proxy re-encryption to multi-hop environment, and then develop a distributed protocol for key distribution; (2) in local group communication, we use multi-recipients encryption to broadcast key information reducing communication cost; (3) we analyze the proposed scheme with the previous schemes and the analysis result indicates that the proposed scheme has advantages with regard to the rekeying cost, storage overhead and computation efficiency.