Authenticated key agreement schemes for multi-server architecture enable a user to register with one registration server and access multiple remote application servers rapidly and conveniently to receive services from them. Several efficient authenticated key agreement schemes have recently been developed for multi-server architecture. However, most of them face many security threats and cannot resist potential attacks. This investigation considers the limitations of previous schemes and proposes a novel efficient and secure multi-server authenticated key agreement scheme that uses Physically Unclonable Functions (PUFs); it is based on a hardware circuit and provides randomness, uniqueness and unclonability to support the lightweight authentication of devices. The proposed scheme protects user privacy and is formally proved to satisfy mutual authentication and session key agreement. This scheme solves problems that were left unsolved in previous works, provides more security, and has a low computational cost.

ABSTRACT Three‐party encrypted key exchange (3PEKE) enables two communicating parties to securely exchange confidential and authenticated information over an insecure network via a trusted server. This investigation presents a novel efficient and secure 3PEKE protocol using a super‐poly‐to‐one trapdoor function. The proposed protocol employs the Diffie–Hellman key exchange and adopts the technique that the clients can publicly exchange the factors for generating the session key without the help of the server to reduce the numbers of transmissions. A round‐efficient version of the proposed 3PEKE protocol is also described. Compared with related approaches, the proposed protocol not only retains security requirements and possesses lower computational cost but also has fewer transmissions and realizes the lower bounds of communications. Copyright © 2013 John Wiley & Sons, Ltd.