Abstract: This paper proposes an efficient remote user authentication scheme based on random nonce which does not require password verification tables.To withstand message replay attacks，the proposed scheme uses random nonce in place of timestamps.Moreover，users are able to freely choose and change their passwords.It has many other advantages such as low computation cost，easy designed，efficient，practical and high security.

摘要： 提出了一种基于随机数的高效远程认证方案，无需存储密码字典或验证表，使用随机数替代时间戳，可以有效抵抗重放攻击。用户可以自由更改密码。方案计算开销小、简洁、高效、实用、安全性高。