An Improvement of the User Identification and Key Agreement Protocol with User Anonymity

Abstract

User anonymity is very important security technique in distributed computing environments that an illegal entity cannot determine any information concerning the user's identity. In 2006, Kumar-Rajendra proposed a Secure Identification and Key agreement protocol with user Anonymity (SIKA). This paper demonstrates the vulnerability of the SIKA protocol and then presents an improvement to repair the security flaws of the SIKA protocol.

Security vulnerabilities of an enhanced remote user authentication scheme

“…Unlinkability is a property which means an adversary cannot recognize whether outputs are from the same user, and this property is important with respect to the privacy problem in the anonymous user identification [5]. However, Yang et al's ERUA scheme cannot provide unlinkability property.…”

“…This paper researches Yang et al's ERUA scheme and then shows that the ERUA scheme not only is still vulnerable to off-line password guessing attack, but also does not provide the unlinkability property [5] and user anonymity because of the identity guessing attack [6,7] unlike their claims. For this reason, Yang et al's ERUA scheme is insecure for practical application.…”