Abstract:

In the scenario of data outsourcing,access control and key update have an important application value.However,it is hard for existing encrypted deduplication schemes to provide flexible and effective access control and key update for outsourcing user data.To solve this problem,an encrypted deduplication scheme with access control and key updates is proposed.First,an efficient access control scheme for encrypted deduplication is designed based on the ciphertext-policy attribute-based encryption and the proof of ownership.It combines access control with proof of ownership and can simultaneously detect whether a client has the correct access right and whole data content only through a round of interaction between the client and the cloud server,effectively preventing unauthorized access and ownership fraud attacks launched by adversaries.The scheme has features such as low computation overhead and few communication rounds.Second,by combining the design ideas of server-aided encryption and random convergent encryption,an updatable encryption scheme suitable for encrypted deduplication is designed.It is combined with the proposed access control scheme to achieve hierarchical and user-transparent key updates.The results of security analysis and performance evaluation show that the proposed scheme can provide confidentiality and integrity for outsourcing user data while achieving efficient data encryption,decryption,and key update.

Key words: cloud storage, encrypted deduplication, access control, key update, updatable encryption