区块链交易数据隐私保护方法

Data Privacy Protection Method of Block Chain Transaction

区块链具有开放性、不可篡改、分布式共享全局账本等优点,但同时这些特性也造成了交易数据隐私泄露问题,严重影响其在许多业务领域的应用,特别是在企业联盟链领域的应用,随着区块链应用的不断发展,如何在区块链平台上对交易数据进行隐私保护是一个非常值得研究的问题。为此,首先对现有的区块链交易数据隐私保护方法进行研究并指出其不足,其次对区块链交易数据隐私保护需求进行定性分析,将每一笔交易数据分为敏感数据和基础数据两部分,建立需求分析矩阵,得出交易隐私保护的本质需求和隐含需求以及可能的应用场景;然后结合对称加密与非对称加密各自的特点以及智能合约的共识特性,设计了一套基于双重加密的区块链交易数据隐私保护方法,该方法主要包括私密数据提供方加密存储交易数据、私密数据使用方解密读取交易数据、私密数据可访问方共享交易数据3个模块,同时对每个模块的工作流程进行了详细论述;最后在蚂蚁区块链平台上结合国际贸易多方共同参与的实际业务对该方法进行验证。测评结果表明,该方法能够实现字段级别细粒度的交易数据隐私保护,能够在链上高效稳定地进行私密数据共享和完成私密数据的全链路操作;在使用4个节点搭建的区块链平台上完成了超过100万笔的交易测试,平均TPS达到了800;相比原来没有使用隐私保护的系统,交易性能并没有明显降低,相比比特币、以太坊等区块链平台,文中使用的区块链平台通过加密后的交易性能得到了几十倍的提升。

Block chain has the advantages of openness,non-tampering and distributed sharing of global accounts,but at the same time,these characteristics also bring about the privacy disclosure of transaction data,which seriously affects its application in many business areas,especially in the field of enterprise alliance chain.With the continuous development of block chain,how to protect the privacy of transaction data on block chain platform is a very worthwhile problem to study.To this end,firstly,the exi-sting methods of data privacy protection in block chain transactions were studied and their shortcomings were pointed out.Se-condly,the requirements of data privacy protection in block chain transactions were qualitatively analyzed.Each transaction data was divided into sensitive data and basic data.A demand analysis matrix was established to obtain the essential and implicit needs of transaction privacy protection and possible application scenarios.Then,combining the characteristics of symmetric encryption and asymmetric encryption and the consensus of intelligent contract,a privacy protection method of block chain transaction data based on double encryption was designed.The method mainly includes three modules:encrypting and storing transaction data by private data provider,using and decrypting private data to read transaction data,and sharing transaction data by private data accessible party.The workflow of each module was discussed in detail.Finally,the method was validated on the Mychain Platform,which combines with the actual business of multi-party participation in international trade.The evaluation results show that the proposed method can achieve fine-grained transaction data privacy protection at the field level,and can efficiently and steadily share private data on the chain and complete the full-link operation of private data.More than 1 million transaction tests have been completed on the block chain platform constructed by four nodes,and the TPS has reached 800.Compared with the original transaction performance without privacy protection,there is no significant reduction in performance.Compared with Bitcoin,Ethereum and other block chain platforms,the performance of the proposed method is improved dozens of times.