Research On Dynamic Data Audit Technology Based On Blockchain

Cloud computing brings convenience to countless users with its robust storage and processing capabilities.Users can outsource data to a cloud service provider(CSP)without having to maintain infrastructure locally,but at the same time,users lose physical control of the data.To ensure that CSP completely stores user data,public data integrity audit techniques often use a centralized audit mode,which authorizes a third-party auditor(TPA)to check the data integrity in CSP.However,due to its single point of failure and performance limitations,it faces significant security risks.The emergence of blockchain technology has provided a new solution for data audit technology,using blockchain to replace the role of TPA in data integrity audit protocols to escape the trust crisis from third parties.Although the blockchain based data audit scheme has excellent performance,some issues still need to be addressed urgently.First,the consensus and verification costs of running systems on the blockchain will increase with the increase in demand,making the blockchain data audit scheme unable to continue running due to the enormous on-chain costs.Secondly,due to the transparency of the blockchain itself,data audit schemes based on the blockchain face challenges of privacy disclosure risks on the chain.In addition,users often dynamically update data after outsourcing data to CSP,so it is essential to support dynamic data operations in blockchain data audit schemes.However,migrating traditional cloud storage-developed dynamic data audit schemes to the blockchain is unsuitable.They all require ample storage proofs or significant storage space,and resource-constrained blockchain links cannot meet these requirements.(1)A dynamic multi-user data collaborative audit scheme based on blockchain is proposed.The scheme uses Diffie-Hellman key exchange technology to achieve user cooperation and share audit costs.On this basis,the Eigen Trust reputation system is used to evaluate the credibility of cooperative users to achieve efficient follow-up audit cooperation to obtain honest users.In order to support the dynamic update of data blocks based on the blockchain,the scheme introduces the PIL structure to realize the full dynamic data integrity verification scheme based on the blockchain while maintaining a small on-chain state and storage proof.The feasibility of this scheme is analyzed by security analysis and performance analysis,and the scheme is compared with the existing scheme.(2)A dynamic data audit scheme supporting privacy protection based on blockchain is proposed.In the scheme,the non-interactive privacy protection audit on the blockchain is realized using the zero-knowledge proof technology based on Schnorr,which can effectively reduce the number of transactions in the blockchain network and improve the system efficiency when generating a verifiable audit certificate.In order to realize the dynamic update of data blocks,the PIL structure is improved in the scheme,and the index space partition method is adopted,which makes it more efficient to find the index information of data blocks while keeping a small memory.The feasibility of this scheme is analyzed by security analysis and performance analysis,and the scheme is compared with the existing scheme.