Research On Attribute-based Searchable Encryption Algorithm On Blockchain

The advent of the era of big data has made cloud servers and the services they provide a research hot topic.Cloud storage has received extensive attention due to its low cost and nearly unlimited data storage space.Data is stored on the cloud server and accessed anytime and anywhere at the same time,data security and access control are also being paid more and more attention,but traditional encryption methods cannot provide users with accurate and efficient search services.Attribute-based encryption technology can provide users with a single-to-numerous,fine-grained data sharing model.However,attribute-based searchable encryption still has problems such as single search keywords,low efficiency,and unreliable search results.Combining decentralized and distributed storage blockchain technology can solve these problems.The main researches content are as follows:(1)A cloud-assisted attribute-based searchable encryption scheme on blockchain is proposed.The scheme uses searchable encryption technology to search encrypted data without decryption.Attribute-based encryption technology is used to achieve fine-grained access control of data,and the immutability of blockchain is used to ensure the security of keyword ciphertext.In the scheme,attribute-based encryption technology is used to encrypt keywords.Keyword ciphertext is stored on the blockchain,and keyword ciphertext and data ciphertext are stored on the cloud server.Based on difficult problem assumptions,it is proved that the scheme satisfies keyword security and trapdoor security under the random oracle model.Numerical experimental results show that the scheme has high efficiency in the key generation phase,trapdoor generation phase,and keyword search phase.(2)An efficient attribute-based encryption data sharing scheme on blockchain is proposed.Attribute-based encryption is used to encrypt the symmetric key of the encrypted data file and store it in the cloud server,which achieves the fine-grained access control of the data.Searchable encryption technology is used to encrypt keywords,and the keyword ciphertext is uploaded to the blockchain.The keyword search by the blockchain ensures the security of the keyword ciphertext,which can effectively solve the existing cloud storage security problems caused by semi-trust.The users only performs simple symmetric decryption,which greatly improves the computing efficiency of the client.It is proved that the scheme can satisfy the indistinguishability of ciphertext and trapdoor under the chosen-plaintext attack.Finally,Numerical experiments show the high efficiency of the scheme.(3)A searchable encryption scheme with attribute-based multi-keyword on blockchain is proposed.The scheme uses multi-keyword searchable encryption technology to achieve effective search of encrypted data,uses attribute-based encryption technology to achieve fine-grained access control of encrypted data,and combines blockchain technology to maintain fairness between users and data owners.The users use to make multiple transactions to get correct search results.Based on difficult problem assumptions,it is proved that the scheme satisfies keyword security and trapdoor security under the random oracle model.Finally,numerical experiments show that the scheme has high efficiency in the keyword ciphertext generation phase and the keyword search phase.