关键词: 访问控制, 属性加密, 密文策略基于属性加密（CP-ABE）, 属性撤销

Abstract: To research the security and efficiency of the access control mechanism, this paper proposes an access control scheme based on the ATP-ABE（Access Tree Pruning Attribute Based Encryption）. When the ATP-ABE algorithm requires its access tree structure of the access policy, it prunes the access tree’s branch which contains the user ID attribute node. It can not only improve the DO’s efficiency of attribute management and control, but also be easy to realize data sharing. Meanwhile it designs the permission access attribute for access tree structure. The DO still retains the key attributes of shared data and can control their shared data completely. The DBDH（Decisional Bilinear Diffie-Hellman） assumption analyzes the security of the ATP-ABE scheme. The results show that compared with the two classical ABE scheme, the ATP-ABE can reduce the system settings, the private key generation, the ciphertext size, the user attribute revocation, the encryption and decryption in the computational overhead, and it gives a quantitative conclusion of the algorithm.

Key words: access control, attribute encryption, Ciphertext-Police Attribute Based Encryption（CP-ABE）, attribute revocation