Improved remote user authentication scheme

Smart card-based authentication is a two-factor authentication mechanism,which is widely used for remote user authentication.In 2006,Liao et al proposed a smart card-based authentication.Based on the modern studies,the safety flaws of Liao et al's program are pointed out.And then an improved authentication scheme based on smart card is proposed.The improved program not only maintains the advantages of the Liao et al's program,but also performs better among efficiency,security and flexibility.