Application Research On Privacy Protection Of Blockchain Transaction Based On Paillier Homomorphic Encryption

With the rise of Bitcoin,a new generation of digital currency,its underlying supporting technology blockchain has also received social attention and is considered to be the cornerstone of the transformation of the information Internet to the value Internet.However,the blockchain technology system relies on the openness and transparency of the global ledger.In order to reach the consensus of all parties,it is necessary to satisfy all the participants to view and verify the transaction data of other participants and jointly maintain the global ledger,which triggered transaction privacy leaks.Therefore,transaction privacy protection research has become a hot topic in current blockchain technology research.Based on the analysis of cryptographic algorithms closely related to blockchain and the advantages and existing privacy protection schemes,this thesis proposes a blockchain transaction privacy protection scheme based on Paillier homomorphic encryption and applies it to Ethereum,a classical blockchain platform.The main work of this thesis is as follows:(1)Design of the Ethereum shield transaction scheme based on Paillier homomorphic encryption.Based on the research and analysis of the existing blockchain transaction privacy protection schemes and classical homomorphic encryption algorithms,this thesis designs the Ethereum shield transaction scheme.According to the characteristics of the Ethereum account model,the amount hidden scheme was designed.Based on the legality verification principle of ciphertext transaction,the transaction verification scheme was designed;the account balance after the transaction is completed can be updated.(2)Design and implementation of the Ethereum shield transaction system based on Paillier homomorphic encryption.According to the characteristics of the hidden transaction,the shield transaction structure and the shield transaction verification rules are constructed,and the Ethereum shield transaction based on Paillier homomorphic encryption is designed and realized,which mainly includes the design and implementation of the transaction initiation module,the design and implementation of the transaction verification module and the design and implementation of the updating account balance module.(3)Test of the Ethereum shield transaction based on Paillier homomorphic encryption.The functional test of the shield transaction validity of the Ethereum secret transaction based on the Paillier algorithm is carried out.The test results show that the scheme designed and implemented in this thesis can protect the privacy of user transactions in Ethereum.Compared with Zcash,the blockchain with the best privacy protection currently,the test results indicate that the scheme designed in this thesis shows better transaction storage performance and higher algorithm efficiency.