Research And Implementation Of Public Key Searchable Encryption Scheme Based On Composite Order Bilinear Pairs

In the continuous pursuit of informatization,the amount of data that people generate and use in daily life and work is exploding,which directly leads to the fact that traditional storage methods can no longer meet the needs of data storage.How to solve the problem of massive data storage and management has become one of the research hotspots.Cloud storage can effectively solve these problems.Cloud storage is an application mode of cloud computing.It can not only store massive amounts of data safely and effectively,but also meet the remote storage needs of users at all times,so it has attracted more and more attention.However,due to the need for confidentiality of data information,people often encrypt data before uploading it to the cloud.However,the traditional retrieval model based on plaintext keywords cannot retrieve it in ciphertext.which poses a great challenge to the cloud storage server how to quickly retrieve the encrypted data.In response to this problem,researchers put forward the concept of searchable encryption.Searchable encryption is a new cryptographic primitive that enables cloud storage servers to directly retrieve data ciphertext without knowing the content of keywords and the content of the data ciphertext searched,which greatly improves the retrieval efficiency of encrypted data.However,searchable encryption also has security problems.It is vulnerable to attacks such as selecting plain text and keyword guessing.Therefore,designing a searchable encryption scheme that can improve retrieval efficiency and ensure data security is one of the research hotspots in the field of cryptography.This thesis focuses on the research and implementation of public key searchable encryption schemes based on composite order bilinear pairs.The specific work is as follows:(1)Research and analyze the security of searchable encryption scheme based on composite order bilinear pairs.Through the analysis of two searchable encryption schemes based on composite order bilinear pairs proposed by Xu et al.and Li et al.,the results show that neither scheme considers the indistinguishability of keyword trapdoors.The indistinguishability of trapdoors is a sufficient condition to resist external offline keyword guessing attacks.Therefore,this thesis proposes an improved searchable encryption scheme on the basis of Li et al.'s scheme.The improved scheme guarantees the trapdoor on the basis of the equivalent computational complexity and good ciphertext and trapdoor size as the original scheme.Indistinguishability and better safety performance.(2)Designed a new public key searchable encryption scheme against inside keyword guessing attacks.Since cloud storage servers can execute test algorithms and store user privacy data,once searchable encryption schemes cannot guarantee the indistinguishability of ciphertexts or trapdoors,malicious cloud storage servers can directly obtain keyword information through inside keyword guessing attacks.In response to this problem,this thesis proposes a new public key searchable encryption scheme based on composite order bilinear pairs.This scheme guarantees the indistinguishability of ciphertext and trapdoor,and has good size,then through simulation experiments,proved that the new scheme has good computational efficiency and better meets the safety needs of users.(3)Implement the improved searchable encryption scheme based on composite order bilinear pairs.Taking the solution proposed in work(1)as the core,a cloud storage environment is simulated on the rented Alibaba Cloud server,and a searchable encryption system is designed using the Springboot framework and the JPBC cryptography package.The system not only meets the basic needs of user file upload,download,and management,but also is designed according to the proposed scheme to ensure the security of user data stored in the cloud storage server.In addition,the system also improves the retrieval rate of encrypted data by the cloud storage server,so that it can quickly respond to user queries.In the end,the system is tested many times and the performance of searchable encryption system is analyzed.