关键词: 密文策略属性基加密（CP-ABE）, 访问控制限制, 重加密

Abstract:

The data shared on the cloud may have conflicts of interest, or one may infer sensitive information from them. This paper chooses the Ciphertext-Policy Attribute-Based Encryption（CP-ABE） scheme that implements attribute revocation through re-encryption and proposes an approach of enforcing access control constraints on such particular data through the re-encryption. This scheme improves the security of existing scheme at less cost while having the ability to prevent users from accessing data that have conflict of interest or revealing sensitive information. Finally, this paper provides security analysis and conduct a test for algorithms in the presented scheme. The analysis shows that the scheme can resist RCCA attacks under the BDHE assumption.

Key words: Ciphertext-Policy Attribute-Based Encryption（CP-ABE）, access control constraint, re-encryption