Research On Forward Secure Searchable Encryption Scheme

With the rapid development of cloud computing,on the one hand,the amount of information that users need to store has exploded,on the other hand,users’ awareness of privacy protection for sensitive information is also growong.Encrypted data outsourcing provides effective solutions to these two needs of users.However,outsourcing encrypted data makes encrypted data lose some of its original characteristics.For example,the cloud server does not have the ability to operate on the encrypted data,and the cloud cannot search for data according to user needs.To solve this problem,searchable encryption came into being.The goal of searchable encryption is to achieve efficient retrieval of encrypted data by users at the cost of well-defined small leaks.Among them,the forward secure searchable encryption scheme has attracted widespread attention because of its security role in the data update process.It ensures that after the file is updated,the newly added file will not reveal the keyword information of the previous file.However,in order to improve security,the existing forward secure searchable encryption schemes often have the following problems: first,the search function is not perfect;second,only single-user search questions are supported.This paper focuses on the research of forward secure searchable encryption schemes based on above problems.The main research contents are as follows:(1)Aiming at the problem of partial data information leakage and single scheme search ability in searchable encryption scheme,a forward security searchable encryption scheme that supports conjunctive keyword search and flexible update types is proposed.Add a cuckoo filter on the server side to further filter the information filtered by the single keyword query to achieve the performance of the conjunctive keyword search.The ciphertext equivalence test technology is used to hide the keyword-file matching information stored in the cuckoo filter to prevent information leakage during the conjunctive keyword search process.Compared with the previous scheme,the proposed scheme provides a keyword conjunctive keyword search function and supports various types of update operations while maintaining efficiency.It is worth noting that this scheme can be improved on the basis of any forward secure searchable encryption scheme that supports a single keyword.(2)Aiming at the problem of secure storage and flexible access to large number of user data in P2 P network,an edge-cloud assisted multi-user forward secure searchable encryption scheme is proposed.This scheme uses proxy re-encryption technology to optimize multi-user searchable encryption and prevents direct transmission of decryption keys between users.By introducing edge-cloud architecture,the system achieves efficient communication and timely response capabilities.The security analysis proves that our scheme achieves the security of selective plaintext attacks based on the DBDH assumption and forward privacy.Comparison and analysis with other schemes show that this scheme has high efficiency in the process of data update,search and trapdoor generation.In addition,due to the adoption of edge cloud architecture,the scheme reduces user consumption in encryption and token generation by approximately 90% and 75%.