Ciphertext Distribution System Based On Lattice Access Control Encryption Algorithm In Cloud Environment

With the increasing popularity of cloud computing technology,data outsourcing services represented by cloud storage are increasingly popular with their low price and simplified management.However,data outsourcing services also have many problems and contradictions.On the one hand,users want to enjoy the convenience of cloud storage while ensuring the confidentiality,integrity and privacy of data.On the other hand,cloud service providers hope to strengthen the management of access,sharing and distribution of cloud data so that to avoid unauthorized users performing some bad behavior through cloud platforms.In cloud storage services,due to the confusing and spreading characteristics of passwords,people often store data in the cloud in an encrypted manner,which makes the data incomprehensible in the cloud,however it is also difficult to perform some common operations,such as data distribution(sharing).At present,there are still some problems in the ciphertext distribution technology in the cloud environment,including how to ensure the safe and efficient transmission of data,ensure the anonymity of users,realize the access control function of the system,and whether it has anti-quantum attack capability.In view of the above problems,this paper conducts in-depth research on the existing ciphertext distribution technology,the new access control encryption algorithm,and the problem of ring learning with errors(RLWE),then propose a single identity system access control encryption algorithm based on RLWE difficult problem.The algorithm includes four roles: key generation and policy control center,data sender,“sanitizer”(cloud storage server)and data receiver.The key generation and policy control center guarantees the function of access control through the design and distribution of the key.The data sender sends the original ciphertext to the “sanitizer”,and the “sanitizer” implements access control function through ciphertext conversion,then sent the converted ciphertext to the data receiver for decryption by means of broadcast.The “sanitizer” as a specific role of the access control encryption algorithm is the core of the algorithm to ensure user anonymity and the implementing of access control functions.Then based on this algorithm,this paper constructs an access control encryption algorithm suitable for multi-identity systems,which is more in line with the needs of practical application scenarios.At the same time,the design of the above algorithm refers to the NTRU public key encryption system,which shortens the encryption and decryption time and is more convenient for practicalapplications.Finally,this paper uses the proposed access control encryption algorithm for multi-identity to implement a ciphertext distribution system in a cloud environment,and compares the functions,performance and security of the system.