Research On Searchable Proxy Re-Encryption Scheme Based On Smart Contracts

With the continuous progress and development of the mobile Internet,it has now entered the era of big data,and data is a resource.Many companies need to analyze user behaviors through massive data,and then customize personalized services to enhance their market competitiveness.Like Tianyancha,the number of companies whose main economic benefits are data transactions has gradually increased.Coupled with the rapid development of data-centric deep learning algorithms,data transactions between companies have become a future development trend.Although current data owners can entrust cloud storage to overcome the limitations of storage capacity and network performance,the traditional data transaction model still has two key issues that need to be resolved.On the one hand,when consumers request cloud storage to retrieve ciphertext data stored by the data owner,cloud storage may tamper with the returned results.On the other hand,when there is no trusted third party,it is difficult to restrict malicious transactions and ensure the fairness of both parties to the transaction.Therefore,it is of practical significance to study how to complete the data transaction plan under the condition of ensuring the above two problems.By studying the existing searchable encryption and proxy re-encryption schemes,this paper proposes a new searchable re-encryption scheme that combines the advantages of the two to solve the problem that the search results may be tampered with during data transactions;then use Blockchain-based smart contracts to build our data transaction system to ensure the fairness of data transactions.The main contributions of the paper are as follows:(1)A new type of searchable re-encryption scheme is proposed,and a security proof is given.The cloud storage provider can convert the ciphertext uploaded by the data owner into a ciphertext that the consumer can decrypt by using the re-encryption key temporarily negotiated between the consumer and the data owner.At the same time,the decryption key of the data owner will not be displayed in this process,and the converted ciphertext can still maintain the ability of keyword search.The advantage of the searchable encryption scheme is to ensure that the data that consumers need can be searched without revealing the plaintext.The advantage of the proxy re-encryption scheme is that it can convert the data that only the data owner can decrypt into the data that only the consumer can decrypt.Therefore,no information will be disclosed to the intermediate cloud storage provider.(2)Based on the above searchable agent re-encryption scheme,a data transaction scheme based on smart contracts is designed.At the beginning of the data transaction,consumers need to pay a deposit.If the required data is obtained,the transaction is complete.Otherwise,the consumer can recover the deposit.The nature of the blockchain is used here to ensure fair data transactions between the three parties.(3)Two schemes designed in Ethereum are implemented,and performance analysis is carried out on them.The experimental results show that,compared with the existing technology,the searchable re-encryption scheme is practical and feasible while considering security and performance;the data transaction scheme based on smart contracts is practical and feasible considering process integrity and performance.