Attribute-Based Authenticated Group Key Transfer Protocol without Pairing

Abstract

Group key establishment protocol is the primary requirement of several group-ware applications, like secure conferences, pay per view, collaborative work space that needs to establish a secure session among a group of participants. However, some of the applications often need to establish a secure session among the participants without knowing their actual identities. In such cases, the legitimacy of participants is decided based up on a descriptive set of attributes usually called as access structure. The participants should have sufficient set of attributes to satisfy the access structure, which are to consider as authenticated and eligible for the group conversation. This paper introducing an attribute based authenticated group key transfer protocol without using bilinear pairing. Group key management based on attributes gives fine-grained access control over the group of members that are authenticated by the set of attributes. The proposed protocol uses, Shamir Secret Sharing and elliptic curve arithmetic instead of bilinear pairing computations. The members are authenticated based on the access structure defined by the session initiator. The group key is securely transferred to only those participants, who are authenticated by their attributes. The authentication process of proposed protocol is information theoretically secure, while the key confidentiality relies on the intractability of Elliptic Curve Discrete Logarithm Problem.