Researches On Data Encryption Algorithms Based On CP-ASBE Of Cloud Storage

Data security problem is one of the key issues that restrict the development of cloud storage. Attribute-based encryption(ABE) is an encryption method that is an effective way to solve the security issues of user’s data. The ciphertext-policy attribute-set based encryption(CP-ASBE) is an extension of attribute-based encryption algorithm, which can realize multiple value assignment of user attributes, and it is more suitable for the cloud storage environment.In the CP-ASBE algorithm, the authorization center is vulnerable to malicious attacks,which becomes the bottleneck of the system security. In this paper, we propose a method of attribute set encryption based on multiple attribute authority(AA). The authorization center is composed of a number of AA, and each AA management part of the key. We designed the process of data storage, key request and data decryption based on the multiple AA system architecture. We improve the access structure tree. Due to the complete key calculation requires the participation of multiple AA, which made the attack more difficult. For many AA system architecture can only resist m attack, we introduced AA trusted measurement method before calculating the decryption key, ensure that there are at least one credible AA, so that the attacker can’t get the complete key, using this way to ensure the ciphertext security.Finally, the security and time cost of the algorithm is simulated and the results show that the algorithm can improve the security of user’s data in the cloud storage environment.