基于属性加密的云存储方案研究

云存储中往往采用属性加密方案来实现细粒度的访问控制，为了进一步保护访问控制策略中的敏感信息，并解决授权中心单独为用户生成密钥而产生的密钥托管问题。该文对访问控制策略中的属性进行重新映射，以实现其隐私性。另外在密钥生成算法中设计一个双方计算协议，由用户产生密钥的部分组件，与授权中心共同生成密钥以解决密钥托管问题。最后在标准模型下对方案进行了安全证明，并进行了性能分析与实验验证，实验结果表明，与已有相关方案相比，虽然为了实现访问控制策略隐藏并且解决密钥托管问题增加了额外的计算负载， 但是由于该文将大部分解密工作授权给云存储中心来执行，因此数据访问者的计算负载较小。

Research on Cloud Storage Scheme with Attribute-based Encryption

Attribute-Based Encryption (ABE) is often used in cloud storage to achieve fine-grained access control. In order to further protect the sensitive information of access control policy and solve the key escrow caused by the authority center generating the private key for users alone. In this paper, the attributes of access control policy are remapped to achieve its privacy. Additionally, a two-party computing protocol in which the user generates partial private key component is devised to solve the problem of key escrow. At last, the security of this scheme is proved in the standard model, and the performance analysis and experiment validation are conducted, which show that although some additional computation overhead is added for achieving the privacy of access control policy and solving the problem of key escrow, the receiver in proposed scheme has smaller computation overhead compared with the existing related schemes because most of the decryption is delegated to the storage center to carry out.