Secure group key management scheme based on dual receiver cryptosystem

Abstract

Providing the confidentiality to the messages delivered between group members in secure group communication model is a critical networking issue. Key management is a challenging task in secure group communication. Tree based group key management scheme is believed to provide a very powerful approach for group key management. In this paper, we provide a new approach to group key management based on the dual receiver crypto system in which a sender can encrypt a message that can be decrypted by two receivers. The proposed scheme is a distributed scheme and uses the key tree to manage the keys. Some of the existing distributed schemes assume the key tree as binary and ternary. Our scheme can be extended to key tree of varying degree. For a group with $n$ users, only two encryptions are needed for rekeying during member join event and ≤ [d/3] logdn (d > 1 is degree) encryptions are required for rekeying upon user leave event. We compare the proposed scheme with the other tree based distributed schemes and show that the proposed scheme is efficient.