Abstract

A Group Key Management is a process or a protocol allows a set of users to establish a common secret via open networks. The common use of this established group key (also termed as conference key) is to permit users to encrypt and decrypt particular broadcast message that is meant for the total user group. So, without loss of confidentiality, a group member can collaborate with other members about information disclosure. In this paper, we propose a group key management protocol that is based on public key cryptography. Based on a notion of signature-based broadcast, we presented a generic construction of Multiple-round Asymmetric key Group key transfer protocol, which can also be used as a broadcast scheme but does not need a trusted dealer to distribute secret keys. By guaranteeing the freshness of authentication messages, the authenticity of the generator of authentication messages and the completeness of the authenticator, the improved protocol can resist various passive and active attacks. The protocol allows the participants in the group to derive a common encryption key, provide the key security and unknown key share properties. Security analysis of proposed scheme is also discussed.

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