International Research Publication House (IRPH)
User authentication is one of the fundamental procedures to ensure secure communication and to share resources over an insecure public network channel. For this a simple and efficient authentication mechanism is required for securing a network system in the real environment. In general, a password-based authentication mechanism provides the basic capability to prevent unauthorized access. Instead of using the password file as conventional authentication systems, many researchers have tried to implement various onetime password schemes using smart cards, time-synchronized token or short message service.