关键词: 云计算, 密文策略属性基加密, 定长密文, 高效性, 灵活性

Abstract: Aiming at the security and privacy of data in the process of data sharing under cloud computing, An attribute-based encryption scheme with high efficiency and flexibility under cloud computing is proposed. The scheme encrypts the cloud storage data using the ciphertext policy attribute base algorithm, and the trusted third party adds the global identity to the user attribute set and aggregates the attribute public key associated with the ciphertext policy with the fixed-length ciphertext strategy so that the The ciphertext length is constant. The scheme effectively prevents the security risks caused by the conspiracy attack on the user data, selects the appropriate encryption algorithm and efficient public key encryption processing way to ensure the privacy of the dynamic data in the data sharing process, and achieves the data security at the lower cost Shared goals.

Key words: Cloud computing, Ciphertext-policy attribute-based encryption, Fixed length ciphertext, Efficiency, Flexibility