A Multi-Party User Authentication and Key Agreement Protocol Based on Public Key Cryptosystem

In this paper, we address the problem of multi- party user authentication and key agreement whereby a party gains assurance of the identity of other parties involved in a protocol for preventing impersonation and unauthorized access. Our scheme utilizes the idea of Buttyan, Nagy proposed multi-party challenge -response protocol. The proposed protocol allows each participant to directly verify all the other parties that were alive during the protocol run. Our protocol uses minimum number of messages required to solve the multi-party entity authentication problem. Specifically, we construct a multiparty secret key generation scheme which employs simple XOR operations. The authenticity of the protocol is assured by a digital signature scheme. Security attributes of our protocol are presented and analyzed as well.