An improved secure remote user authentication scheme using smart cards with check digits

The advancement of communication technology resulted in increasing number of security threats over public Internet on remote servers. In 2014, Shipra et al. proposed an improved remote user authentication scheme using smart cards with check digits. Shipra et al. claimed that their scheme is secure and efficient against all major cryptographic attacks. Unfortunately, their scheme is vulnerable to some of the cryptographic attacks, particularly “online password guess attack” as discussed in this manuscript. As a part of our contribution, we propose a robust and extra secure authentication scheme for remote users based on smart cards with check digits, with slight increase in the cost. Security is the fundamental compared to complexity, since complexity can be easily manage with improved technology.