区块链数据保密查询的不经意传输协议  

Oblivious Transfer Protocol for Confidentiality Query of Blockchain Data

作　　者：刘新[1] 胡翔瑜 徐刚 陈秀波[3] LIU Xin;HU Xiangyu;XU Gang;CHEN Xiubo(School of Information Engineering,Inner Mongolia University of Science and Technology,Baotou,Inner Mongolia 014010,China;College of Information,North China University of Technology,Beijing 100144,China;State Key Laboratory of Network and Switching Technology,Beijing University of Posts and Telecommunications,Beijing 100876,China)

机构地区：[1]内蒙古科技大学信息工程学院,内蒙古包头014010 [2]北方工业大学信息学院,北京100144 [3]北京邮电大学网络与交换技术国家重点实验室,北京100876

出　　处：《计算机工程》2022年第10期13-20,共8页Computer Engineering

基　　金：国家自然科学基金(92046001);内蒙古自治区自然科学基金(2021MS06006);内蒙古自治区科技重大专项(2019ZD025);内蒙古自治区纪检监察大数据实验室开放项目(IMDBD2020020);包头市科技计划项目(YF2020013);北京市教委基本科研业务费资助项目(110052972027);北方工业大学科研启动基金(110051360002)。

摘　　要：在区块链数据存储与查询过程中,由于区块链的透明性和公开性,全网所有用户均有可能获取查询者的数据信息,存在泄漏查询者隐私数据的风险。采用区块链链上-链下存储思想,设计区块链数据存储模型,引入代理重加密机制,将存储者加密后的数据分布式存储在链下,将存储者发送的索引信息和Merkle树根哈希值存储在链上,确保了数据的完整性、可靠性和可验证性,并减少了区块链数据对存储资源的占用。利用椭圆曲线加密算法设计区块链数据保密查询的不经意传输协议,使得全网所有用户均无法获取查询者的数据信息,保护了区块链数据传输过程中查询者的隐私。分析结果表明,该协议中查询者完成一次区块链上的不经意传输仅需2n+2k+2次椭圆曲线乘法运算,相比于现有不经意传输协议具有存储空间小、计算复杂度低等优势,并且在相同长度的密钥下具有更高的安全性。During the data storage and query of a blockchain,owing to the transparency and openness of the blockchain,all users of a network may obtain information regarding the inquirer;thus,confidential information regarding the inquirer may be exposed.This study adopts the idea of a blockchain on-chain off-chain storage,designs a blockchain data storage model,introduces a proxy re-encryption mechanism for storing the encrypted data of the storer off-chain in a distributed manner,and stores the index information sent by the storer as well as the hash value of the root of the Merkle tree on the chain;this,in turn,ensures the integrity,reliability,and verifiability of data and also reduces the utilization of storage resources by the blockchain data.The elliptic curve encryption algorithm is used to design an Oblivious Transfer(OT)protocol for the confidential query of blockchain data,which prevents all the users in the entire network from obtaining the inquirer’s information;this protects the privacy of the inquirer during data transmission.Analysis results reveal that the inquirer requires only 2n+2k+2 elliptic curve multiplication operations to complete an OT on the blockchain when using this protocol.Compared with existing protocols,this OT protocol requires a smaller storage space,features lower computational complexity,and offers higher security for the same key length.

关 键 词：区块链 保密查询 链上-链下存储模型 不经意传输 椭圆曲线加密算法 

分 类 号：TP309.2[自动化与计算机技术—计算机系统结构]