基于CP-ABE的隐藏属性外包解密访问控制

传统的属性基加密方案中数据拥有者将访问结构和密文保存在一起，于是用户收到密文消息的同时也收到了访问结构，但访问结构本身就可能包含数据拥有者的隐私信息。本文提出一种基于密文策略属性基加密(Ciphertext-Policy Attribute-Based Encryption, CP-ABE)的隐藏属性外包解密访问控制方案。该方案既能隐藏数据拥有者制定的访问控制策略中的属性，同时将计算密集型解密操作交给代理服务器完成，又能保证未经授权的属性授权中心或代理服务器不能独自解密共享的加密数据。

Hidden Attribute Outsourced Decryption Access Control Scheme Based on CP-ABE

In conventional attribute-based encryption schemes, the data owner embeds the access structure to the ciphertext, thus the user receives the ciphertext with the access structure, however the access structure itself might contain private information of the data owner. This paper proposes a hidden attribute outsourced decryption access control scheme based on CP-ABE (Ciphertext-Policy Attribute-Based Encryption). The scheme can not only hide the attributes of the access control policy specified by the data owner, but also deliver the computation intensive decryption operations to the proxy server and guarantee that the unauthorized attribute authorization center or the proxy server can not decrypt the shared encrypted data alone.