A Secure Three-factor Authenticated Key Agreement Scheme for Multi-Server Environment

Multi-server authenticated key agreement schemes have attracted great attention to both academia and industry in recent years. However, traditional authenticated key agreement schemes in the single-server environment are not suitable for the multi-server environment because the user has to register on each server when he/she wishes to log in various servers for different service. Moreover, it is unreasonable to consider all servers are trusted since the server in a multi-server environment may be a semi-trusted party. In order to overcome these difficulties, we designed a secure threefactor multi-server authenticated key agreement protocol based on elliptic curve cryptography, which needs the user to register only once at the registration center in order to access all semi-trusted servers. The proposed scheme can not only against various known attacks but also provides high computational efficiency. Besides, we have proved our scheme fulfills mutual authentication by using the authentication test method.