A survey of authenticated key agreement protocols for multi-server architecture

This paper presents a comprehensive survey of authenticated key agreement protocols, which have been proposed for multi-server architectures. The growing use of cloud-based services has made multi-server authentication protocols a necessity. For a brief insight into the topic, the break-fix history of these protocols, vital functional and security requirements have been summarized. Protocols are categorized based upon the cryptographic mechanism used. To evaluate the trade-off between security and performance, comprehensive analysis concerning performance and security of multiple protocols, from each category, has been carried out. Some profound results of this survey include: 1) the majority of existing protocols engage the registration server (RS) in the mutual authentication, which results in extra communication overhead and creates a computational bottleneck on RS end. Secondly, majority of the hash-based protocols with offline RS are vulnerable to key compromise impersonation attacks. Thirdly very few schemes consider the efficient and demanded revocation of compromised participants. Finally, among all these protocols, pairing-based designs are the most computationally expensive.