Abstract
Cloud-based services have become part of our day-to-day software solutions. The identity authentication process is considered to be the main gateway to these services. As such, these gates have become increasingly susceptible to aggressive attackers, who may use Denial of Service (DoS) attacks to close these gates permanently. There are a number of authentication protocols that are strong enough to verify identities and protect traditional networked applications. However, these authentication protocols may themselves introduce DoS risks when used in cloud-based applications. This risk introduction is due to the utilization of a heavy verification process that may consume the cloud's resources and disable the application service. In this work, we propose a novel cloud-based authentication protocol suite that not only is aware of the internal DoS threats but is also capable of defending against external DoS attackers. The proposed solution uses a multilevel adaptive technique to dictate the efforts of the protocol participants. This technique is capable of identifying a legitimate user's requests and placing them at the front of the authentication process queue. The authentication process was designed in such a way that the cloud-based servers become footprint-free and completely aware of the risks of any DoS attack. (C) 2014 Elsevier Ltd. All rights reserved.