An enhanced verifier-free password authentication scheme for resource-limited environments

To realize secure access to multimedia anywhere, anytime, and with any devices, we need efficient authentication mechanisms suitable for resource-limited environments. Password authentication is regarded as one of the most widely used authentication mechanisms for its convenience, easy implementation, and user-friendliness. Up to now, many verifier-free password authentication schemes that can resist stolen-verifier attacks have been proposed, and each has its pros and cons. Recently, Wang et al. showed that two new verifier-free password authentication schemes are vulnerable to an off-line password guessing attack, a forgery attack, and a denial-of-service attack, and then proposed an improved scheme for the real application in resource-limited environments. Unfortunately, we find that Wang et al.´s scheme is still vulnerable to several attacks. Herein, we propose an enhanced verifier-free password authentication scheme for resource-limited environments with better security strength.