Research On Privacy Protection And Fairness Based On Searchable Encryption In Blockchain

With the rapid development of big data and cloud computing technologies,the volume of data has increased,and this trend poses a huge challenge to resource-constrained users.To reduce the storage load,users often upload files to cloud servers.However,files may contain sensitive data,and many users perform encryption operations before outsourcing the data,generating a large amount of ciphertext,but too much ciphertext is not conducive to retrieval and decryption.Since searchable encryption allows users to search in ciphertexts,it has been widely used in recent years,providing convenience but also bringing some pitfalls.First,the original searchable encryption has transaction unfairness in practical applications: users need to pay a service fee before they can get the search results.When the server returns wrong results,the user not only cannot get the data,but also loses the whole service fee in this transaction.In addition,the data owner may upload the file multiple times,and the static index and token will expose more information during the update process,increasing the probability of successful adversary attacks.To solve the above problems,this paper proposes a privacy protection and fairness scheme based on searchable encryption in blockchain.The main contributions made are as follows.(1)To address the behavior of malicious servers returning wrong results or incomplete search results,this paper proposes block This paper proposes a fairness scheme for implementing searchable encryption in blockchain for transactions.The scheme introduces blockchain system,which can quickly track the location of The solution introduces a blockchain system,which can quickly track the location and automatically verify the results with the help of blockchain to see whether the results satisfy the correctness and integrity,and achieve the purpose of resisting The purpose of malicious servers is to avoid losses for users.It also introduces a deposit system to punish malicious servers.Once the server is found to be malicious,the deposit paid by the server will be withheld.Verification can also effectively reduce users’ computation and improve the security and fairness of searchable encryption.(2)In response to the privacy leakage caused by multiple uploads of files by data owners,this paper proposes a blockchain in privacy protection scheme based on searchable encryption.This scheme checks the keyword search history through the status table,and if the keyword keyword has access history,a new token is generated,which ensures that the server receives a different token each time.The server receives a different token each time.Even if the same keyword is searched multiple times,the server will get different tokens,so it is very difficult to find the relationship between the new token relationship with the original file is very difficult,and the new token does not reveal any information about the old file.This mechanism The new token does not reveal any information about the old file.This mechanism provides the system with forward security and enhances the privacy protection of the system.