关键词: 密码学, 认证, 协议, 椭圆曲线密码系统, 密钥协商, 口令

Abstract: Password-based authentication and key exchange protocol have been widely used in various network services due to easy memory of password. Unfortunately, password-based authentication scheme also suffers from attacks because of the low entropy of password. In the year 2011, Islam et al.（ISLAM SK H, BISWAS G P. Improved remote login scheme based on ECC. IEEE-International Conference on Recent Trends in Information Technology. Washington, DC: IEEE Computer Society, 2011： 1221-1226）proposed an improved remote login scheme based on Elliptic Curve Cryptography (ECC).Whereas, the scheme was vulnerable to stolen-verifier and impersonation attacks and failed to provide mutual authentication. Therefore, the authors proposed a password-based Remote Authentication with Key Agreement (RAKA) protocol using ECC to tackle the problems in Islam et al.'s scheme. RAKA was based on Elliptic Curve Discrete Logarithm Problem (ECDLP) and needed to compute six elliptic curve scale multiplications and seven hash function operations during a protocol run. The efficiency improves by about 15%〖BP(〗 percent〖BP)〗. It is more secure and efficient than Islam et al.'s scheme.

Key words: cryptography, authentication, protocol, Elliptic Curve Cryptosystem (ECC), key agreement, password