Research On Proxy Re-encryption With Keyword Search Schemes In Cloud Computing

With the widespread use of cloud computing technology,as well as the integration of network space and the real world to further deepen,the Internet and people's life are closely linked.A large number of users choose data outsourcing services due to its convenience and interactivity.As many businesses and individuals choose data outsourcing services,the storage data increase exponentially.The data outsourcing services which can not only access and share the data between users,but also save the cost of local data storage.To protect the sensitive information,the users can encrypt the data locally and send to the cloud server.Therefore,at present,how to retrieve the cipher-text data in the cloud and how to improve the retrieval efficiency are the urgent problems to be solved.In view of the above problems,the proxy re-encryption with keyword search is used in this paper to solve the related problems of the retrieval of the encrypted data in the cloud server and has carried on the following related work:A novel proxy re-encryption with keyword search scheme based on bilinear pairings is proposed.The user data after being divided into three parts,i.e.,file,file index and the keyword corresponding to file,will be encrypted respectively.In the re-encryption phase,the advanced scheme does not need to re-encrypt partial file ciphertext,but re-encrypt the ciphertext of keyword corresponding to file.The scheme can improve the computation efficiency in comparison with congener schemes.It is proven to be with indistinguishability under adaptive chosen keywords attack in Hash Diffie-Hellman assumption.Furthermore,the scheme does not use any strongly-unforgeable one-time signature,making it more effective and safer in the cloud environment.Traditional public key encryption schemes are usually in the form of one to one between encrypted and decrypted user which do not meet the requirements of fine-grained access control.On the basis of in-depth analysis of the related work,an attribute-based proxy re-encryption scheme is proposed.In the proposed scheme,the keyword search function is implemented among the users with the same attribute in a multi domain.The cipher-text of an access structure can be converted to a cipher-text of the other access structure.The proposed scheme is proven to be secure in random oracle model.The cloud storage provider is unable to obtain any plaintext in the whole process.