云计算中基于可转换代理签密的可证安全的认证协议

云用户与公有云之间的双向认证是云计算中用户访问公有云的重要前提.2011年,Juang等首次提出了云计算环境下采用代理签名的认证协议,其优点是用户只需到私有云中注册,然后在私有云的帮助下通过公有云的认证.但是,该方案存在3个缺陷:1)为保护用户的隐私,每次会话都需更新用户公钥;2)当私有云中的许多用户同时登录不同的公有云时,私有云会遭遇网络拥堵;3)用户的私有云与访问的公有云之间需要预先共享秘密.为弥补上述不足,提出了一种保护用户隐私的可证安全的可转换代理签密方案,基于该方案设计了一种一轮云计算认证协议.新方案的优点在于用户向私有云注册后,就能通过公有云的认证,而不需要私有云的帮助,并且它还能保护用户的隐私性、抗抵赖性.协议不需要在每次会话开始前更新用户公钥,同时私有云与访问的公有云之间不再需要预先共享秘密.在随机谕言机模型下证明了新协议的安全性,并且比较说明新协议在效率方面优于Juang等的协议.

Provably secure authentication protocol based on convertible proxy signcryption in cloud computing

Mutual authentication between the user and the public cloud is essential requirement for the user to access the public cloud in cloud computing.In 2011,Juang et al.proposed a first authentication scheme based on proxy signature.The advantage of the scheme is that the user only needs to register on his home service cloud(HSC),and can pass through the authentication of the public cloud with the help of his HSC.However, their scheme has three weaknesses:1)the user’s HSC needs to update the user’s public key in each session to protect the user’s privacy;2)HSC may suffer from network jam when many users in the same HSC need to register on different public clouds simultaneously;and 3)a secret key should be shared between HSC and visiting cloud.To overcome these weaknesses,a provably secure convertible proxy signcryption for privacy preserving is proposed.Based on this scheme,a novel one-round authentication protocol is proposed,which the user only needs to register on his HSC,and can pass through the authentication of the visiting cloud without the help of his HSC.On the other hand,the proposed protocol can provide some nice properties,such as user privacy protection, non-repudiation,without updating the user’s public key,and secret key does not have to be shared between HSC and visiting cloud.In addition,the proposed scheme is provably secure in the random oracle model,and is more efficient than Juang et al.’s scheme.