Research On Privacy Protection Technology Of Electronic Scoring Based On Blockchain

With the rapid development of Internet technology,traditional paper voting is gradually replaced by electronic voting.Electronic scoring,as a special electronic voting method,is also being increasingly used.Electronic scoring is good for reducing the cost of scoring activities.However,there are also more shortcomings in data storage and data processing,such as: scoring privacy(including scorer information and scoring results)is maliciously intercepted and tampered,and the accuracy of scoring results needs to be verified.Blockchain has two characteristics of non-tampering and decentralization,which can well avoid the phenomenon of data tampering in electronic scoring,but all data will be made public,and there is a risk of rating privacy leakage.Based on this,the rating privacy can be effectively protected by using Paillier homomorphic encryption algorithm to encrypt the rating plaintext.However,the scoring results often involve fractional operations such as calculating averages,which require high data accuracy,and the application of the traditional Paillier algorithm is limited to integers only,which cannot meet the specific needs of electronic scoring scenarios,so it is necessary to study electronic scoring schemes applicable to fractional operations.By combining proof of zero knowledge techniques,the verifiability of scoring results can be guaranteed,but there are duplicate and invalid scores in scoring,and the data need to be filtered to better improve the accuracy and validity of scoring results.This thesis proposes a new electronic scoring scheme that solves three problems in traditional electronic scoring schemes: leakage of users’ private data,low accuracy of scoring data,and inability to publicly verify scoring results.By storing data in the form of ciphertext on the blockchain and designing a smart contract to control the process of the electronic scoring scheme,it replaces the traditional trusted third-party scoring agency and effectively prevents the leakage of scoring privacy.Based on the traditional Paillier algorithm,this thesis researchs the characteristics of homomorphic encryption on integers and proposes an improvement scheme to extend the data accuracy to the fractional range to support scoring activities with different data accuracy.In addition,by studying smart contracts and proof of zero knowledge techniques and designing a corresponding incentive scheme: by providing proof of scored scores,the rater can obtain a reward for completing the scoring task and validate the scoring results.By introducing the incentive scheme,people can prevent raters from abandoning the scoring behavior on the one hand,and verify the validity of scoring results on the other hand.By combining blockchain and cryptography technologies,the privacy protection capability of the existing electronic scoring scheme can be enhanced and the risk of data leakage and tampering can be avoided.The experimental results and analysis show that the new electronic scoring scheme meets the security standards of electronic scoring schemes and has higher execution efficiency and data accuracy.The scheme is also applicable to other scenarios that require higher data privacy and accuracy,such as medical and financial data sharing calculations.