Research On Searchable Encryption Scheme Based On Authorization

The popularity of cloud storage services enables data owners to store data on cloud servers,thereby saving local storage space.If the data owner shares the data in plaintext,the privacy of the data will be leaked;if the data owner shares the data in ciphertext,it will lead to the problem of how to retrieve the ciphertext data.Therefore,how to retrieve the ciphertext data becomes an urgent problem.In the searchable encryption service,the cloud server may return illegal ciphertext files to the data user,the data owner may upload illegal ciphertext files,and verify the identity of the data user.Aiming at these problems,this paper proposes research on searchable encryption scheme based on authorization.The main research contents are as follows:(1)An authorized searchable encryption scheme against keyword guessing is proposed.The data user and the data owner jointly authorize the authorization server to enable the authorization server to authenticate the data user.At the same time,the authorization server uses the authorization information to assist the data user in validating the ciphertext returned by the cloud server.(2)An efficient and authorized certificateless searchable encryption scheme is proposed.In the schemes,the authorization server can verify the identity of the data user,and can assist legitimate data users to verify the validity of the search results returned by the cloud server.At the same time,the cloud server can verify the legitimacy of the data owner's identity through the signature of the data owner's ciphertext index.(3)A certificateless searchable encryption scheme for designated-verifier is proposed.The data user uses the public key of the authorization server designates the authorization server as the designated verifier,and verifies the returned ciphertext.The data owner signature the uploaded ciphertext file,and the cloud server can verify the identity of the data owner,preventing the data owner from denying the uploaded ciphertext file.