Research On User Identity And Data Privacy Protection In Consortium Blockchain

Blockchain technology,as a distributed ledger technology based on cryptography,decentralization,trustlessness,and high security,has attracted much attention due to its numerous advantages and has gradually become a global focus.However,an important issue in the blockchain is privacy protection of blockchain.Since the ledger in blockchain is public and transparent,it means that users’transaction details and other sensitive information are shared across the entire blockchain network.This open and transparent transaction data poses a serious threat to users’ privacy.Therefore,privacy protection has become an important challenge in the blockchain.To solve the issue of identity privacy leakage during the blockchain transaction process and the issue of transaction data privacy,this thesis proposes two solutions for each of the two issues.The main work is as follows:(1)Aiming at the problem of user identity privacy leakage in the consortium blockchain Fabric,a certificateless signature based identity privacy protection scheme for Fabric is proposed.By combining the characteristics of the channel mechanism in the Fabric,and by using both long-term and short-term pseudo-identities jointly,it can be avoided that identity certificate management and key management problems occur in the channel by utilizing uncertificated signature algorithms.As a result,the scheme ensures strong anonymity of node identity and achieves user identity privacy protection.Through theoretical analysis,it is proved that the scheme can resist common public key replacement attacks and tampering attacks,and has the characteristics of signature unforgeability and guaranteed node anonymity,etc.Finally,by comparing with the efficiency analysis of other schemes,this scheme ensures high signature and verification efficiency while having strong anonymity.(2)To address the privacy issue of users’ transaction data in the Fabric,a consortium blockchain data privacy protection scheme based on elliptic curve integrated encryption algorithm is proposed.The improved elliptic curve integrated encryption algorithm is used to encrypt the transaction data that users need to send on the consortium blockchain to achieve the purpose of protecting user data security and privacy.And the application of elliptic curve integrated encryption algorithm also ensures that we can reject illegal input in time to guarantee data security.In summary,this thesis proposes two schemes to protect the identity and privacy of users on the consortium blockchain,using both certificateless signature and elliptic curve integration encryption algorithms.These two schemes complement each other and achieve secure and privacy-protected access to the Fabric application.