Privacy-secure Transfer And Payment System Based On Regulatory Blockchain

The traditional transfer payment system is established by a third-party organization to store and supervise the data.The security of the transaction data depends entirely on the trust of the third party,which exists with many hidden dangers.The blockchain has the characteristics of decentralization,user anonymity,collective maintenance,and data transparency.It can solve the problem of over-reliance on the third-party in the transfer payment transaction,and can replace the storage and supervision functions of third-party organizations.Although the blockchain technology anonymizes the user's identity,it does not protect the data such as the transaction amount.This allows the attacker to expose the user's true identity through behavior-based clustering analysis.Therefore,it is necessary to protect the transaction data and the identity of the user.Due to the complete decentralization of the blockchain,illegal transactions on the chain cannot be effectively regulated,so it is necessary to study the supervision of blockchain technology from a technical perspective.Based on homomorphic encryption and ring signature technology,this thesis studies the privacy protection and controllable anonymity of blockchain,proposes corresponding solutions,and applies the designed scheme to the transfer payment transaction scenario.This dissertation proposes a privacy-secure transfer payment agreement based on regulatory blockchain to solve problems of privacy protection and supervision in transfer payment transactions.The main idea is to hide some information that can be obtained from blockchain public data without affecting normal system operation,so as to increase the difficulty of data analysis.Meanwhile,regulators can supervise all transactions.To be specific,this dissertation mainly completes the following tasks: a transfer payment transaction scheme based on blockchain is proposed,which clarified the privacy protection security problem in transaction;a privacy protection scheme based on homomorphic encryption is proposed for the issue of transaction amount disclosure,the homomorphic nature of the algorithm can verify the validity of the transaction in the case of protecting the transaction data;on the basis of CryptoNote protocol,a hybrid scheme based on the revocable anonymous ring signature is proposed for the issue of transaction address disclosure.By using the characteristics of the ring signature,the address of the transaction initiator can be effectively protected,and the signer needs to encrypt the private key to participate in the signature construction,which ensures that the anonymity can be revoked under special circumstances;a two-level regulatory framework is proposed for the issue of transaction supervision on the blockchain,and the regulator can retain the responsibility of the buyer and seller on the blockchain.Compared with other existing blockchain privacy protection schemes,the advantage of this scheme is that it realizes the privacy protection of the transfer payment transaction data and user identity and the regulation of the transaction under the premise of being transparent to the user.This dissertation theoretically analyzes the correctness and security of the protocol,and finally completes the performance test and security analysis of the system through experiments.