基于同态加密的跨链交易数据隐私保护

Privacy Protection Based on Homomorphic Encryption for Cross-chain Transaction Data

为了解决区块链跨链交易数据隐私问题,本文提出了一种基于同态加密的隐私保护方案.该方案改进了同态加密算法以支持浮点数运算,同时保留了原算法加法同态特性,并支持任意次数的加法运算,以实现对跨链交易金额的隐私保护.为了防止同态加密的私钥管理不当或丢失对交易安全性构成威胁,引入了基于Shamir秘密共享的私钥共享机制.该机制通过增加ECDSA数字签名对私钥份额进行验证,防止不可信节点发送恶意的值来恢复私钥,同时考虑节点掉线或离开后私钥份额的动态更新,从而防止节点串谋.经过安全性分析和实验验证,结果表明所提出的方案能有效保护跨链场景下的交易隐私.

To protect data privacy in blockchain cross-chain transactions,this study proposes a privacy protection scheme based on homomorphic encryption.The scheme improves the homomorphic encryption algorithm to support floatingpoint operations while retaining the additive homomorphic property of the original algorithm,and it supports any number of addition operations to realize the privacy protection of cross-chain transaction amounts.To prevent security threats to transactions posed by mismanagement or loss of the private key with homomorphic encryption,a private key sharing mechanism based on Shamir’s secret sharing algorithm is introduced into the scheme.This mechanism prevents untrustworthy nodes from sending malicious values to recover the private key by adding ECDSA digital signatures to verify the private key share.It also considers the dynamic update of the private key share after a node drops or leaves to prevent node collusion.Security analysis and experimental verification show that the proposed scheme can effectively protect privacy in cross-chain transactions.