An Efficient and Fully Robust Group Key Agreement

Abstract: An efficient and fully robust group key agreement protocol (GKA) enables a group of authenticated users to communicate over a reliable broadcast communication medium. All non-faulty nodes will form a cyclic group and hence have the same view of the message which is broadcasted and the faulty nodes cannot view that message. The standard encryption-based group key agreement protocol can be robust against an arbitrary number of node faults, because the performance deteriorates if some nodes fail during the protocol execution..By making each node to enter with the help of a nonce which is an arbitrary number that is used only once in a cryptographic communication and it will protect the malicious insiders that may disturb the group communication. The elliptic curve digital signature algorithm is used for establishing the group key and the proposed protocol has O(log n)-sized messages and expected round complexity close to 2, assuming random node fault and also it is secure under the (standard) Decisional Square Diffie-Hellman assumption.

Keywords: Group key agreement, fault-tolerance, security, Secure Communication, nonce.