一种高效的移动云服务环境下隐私保护认证协议

为了解决移动云服务环境的互相认证和隐私保护问题，设计了一种改进的移动云服务环境下隐私保护认证协议.该协议结合基于身份的签密技术和多服务器认证技术，保证用户只需注册一次，就可以访问多个移动云服务提供者，同时认证过程不需要可信第三方参与；该协议在移动终端未使用计算复杂度高的双线性对运算和映射到域上的hash运算，其计算效率显著提高. 通过理论分析和实验结果可知:该协议与目前已有的同类协议相比，在移动端的计算时间为45.242 s，其计算效率约为已有同类协议的2倍；具有用户匿名和不可追踪等安全性质；能够抵抗错误口令登录、更改攻击. 

Efficient Privacy-Preserving Authentication Protocol for Mobile Cloud Computing Services

To address the problems of mutual authentication and privacy preservation in mobile cloud computing (MCC) services, an efficient and provably secure privacy-preserving authentication protocol, based on an identity-based signature technique, is proposed for MCC services, achieving authentication without the help of a trusted third party. Additionally, because a multi-server authentication technique has been employed in the proposed scheme, mobile users can access all registered servers, which are registered only once at the registration centre. In the proposed scheme, time-consuming operations such as bilinear pairings and map-to-point hash are avoided in the resource-constrained mobile device. Thus, the running time of our scheme in the mobile device is 45.242 s, and the computational efficiency is approximately twice as fast as existing related schemes. Security analysis shows that our scheme can provide a variety of security features, such as user anonymity and untraceability. Moreover, it can resist wrong password loginand update attack