Abstract:

The attribute-based encryption mechanism provides a flexible access control scheme for data sharing and management in a cloud environment. However, the traditional attribute-based encryption scheme has the problems of high decryption complexity and difficulty in attribute revocation, which leads to limited application of the attribute-based encryption mechanism in practice. Aiming at the above problems, this paper proposes a ciphertext-policy attribute-based encryption scheme, which only needs to update the corresponding secret in the attribute revocation process. The text component effectively reduces the computational cost of the ciphertext update, and the attribute revocation process is transparent to the user. The user does not need to participate in the ciphertext and the key update, thereby reducing the impact of the attribute revocation on the user. At the same time, the decryption agent is introduced to outsource the part with large computational cost in the decryption process to the server, thereby reducing the decryption overhead of the client. Security analysis shows that this scheme can resist joint collusion and selective plaintext attacks. Finally, through comparative analysis, the scheme has certain advantages in the computational overhead of the ciphertext update and decryption process.

Key words: attribute-based encryption, access control, attribute revocation, outsourcing decryption