关键词: 同态加密, 访问控制, 密文策略, 属性加密

Abstract: Attribute encryption scheme is extremely suitable for data access control in cloud storage environment, but the security problem of user private key is still a very challenging problem, which affects the practical application of attribute encryption. Aiming at this problem, the paper proposes a ciphertext-policy attribute encryption scheme based on homomorphic encryption. The attribute authorization center and the cloud service center have secret coordinates containing the private key information of the respective systems. The two use the secret coordinates of each to perform the secret calculation of the two-point and one-line slope to interactively generate the user private key. The analysis results show that the proposed scheme greatly reduces the number of communication interactions required to generate the user key while eliminating the single key generation mechanism, thereby reducing the risk of secret information leakage during the interaction process.

Key words: homomorphic encryption, access control, ciphertext strategy, attribute encryption