基于策略隐藏属性基加密(ABE,attribute based encryption)算法,提出了一种适用于云环境的访问控制方案PHACS(policy hiding access control scheme).该方案在基于属性访问控制的基础上,借鉴单向匿名密钥协商的思想,既能够进行细粒度的访问控制,又有效地避免了由于访问控制策略泄漏造成的隐私问题.另外,PHACS中策略表达支持任意门限或布尔表达式,解密操作能够在计算能力受限的设备上实施.本文对方案的安全性进行了证明,并通过理论与实验分析表明PHACS能很好地适应云存储中数据共享的访问控制.
In this paper, we propose an access control scheme for cloud storage by constructing a policies-hidden attribute-based encryption scheme. This scheme can not only protect the privacy of shared data, but also prevent the disclosure of access policy. Meanwhile, the access policy can be expressed with any arbitrary access formula, and the decryption operations can be implemented in devices with limited computing power. The theoretical analysis and exper- imental results show that we find our scheme is well suitable for access control in the cloud storage.