可证明安全的基于RSA的远程用户口令认证协议

身份认证是确保信息系统安全的基本手段,基于RSA的认证协议由于实用性较强而成为近期研究热点.讨论了Xie等提出的一个基于RSA的双因子远程用户认证协议,指出该协议不能抵抗重放攻击和密钥泄露仿冒攻击,无法实现所声称的安全性,并且存在用户隐私泄露和可修复性差问题,不适于实际应用.给出一个改进方案,在随机预言机模型下,基于RSA假设证明了改进方案的安全性.与现有的基于RSA的同类协议相比,改进协议在保持较高效率的同时,首次实现了可证明安全性,适用于安全需求较高的移动应用环境.

Provably secure RSA-based remote user authentication protocol using passwords

With identity authentication becoming an essential mechanism to ensure robust system security in information systems, RSA-based authentication protocols have been studied intensively for their great practicality. This paper points out that a recent RSA-based remote user two-factor authentication protocol proposed by Xie et al. cannot achieve the claimed security and reports its following flaws: (1) It is vulnerable to replay attack and key compromise impersonation attack; (2) It suffers from the problem of user privacy violation and poor repairability. As our main contribution, an improved scheme is put forward and formally proved secure under the RSA assumption in the random oracle model. As compared with other related schemes, our scheme is the first one that can achieve provable security while keeping the merit of high performance. Consequently, our scheme is more well-suited for mobile application scenarios where resource is severely constrained and security is particularly concerned.