Abstract-Password-based authentication schemes are convenient, but vulnerable to simple dictionary attacks. Cryptographic secret keys are safe, but difficult to memorize. Recently, biometric information has been used for authentication schemes because it is difficult to copy, share, forge, and distribute. In 2011, Das proposed a biometric-based authentication scheme, but it has various vulnerabilities such as replay attack, denial-of-service attack, user impersonation attack, and password change problem. To solve these problem, Jiping et al. Index Terms-User authentication, biometric-base scheme, client/server system, cryptanalysis on authentication scheme.