基于区块链的零知识位置证明系统设计

智能终端设备及定位技术的发展催生了许多基于位置的服务，如定点打卡服务（访问特定地点获取相应的奖励），这导致非法用户为了获取利益对位置服务器进行位置欺骗。因此，需要对用户提供的位置证书进行验证。但现有的位置证明系统在验证用户位置证书的同时对用户隐私保护并不周全，且用户对位置证书的控制并不灵活。基于区块链技术，提出一种分布式位置证明系统架构；进而在此架构基础上，引入零知识证明，提出一种零知识位置证明协议。架构与协议组成的零知识位置证明系统允许用户根据需求，自由选择披露的证书内容及位置精度，实现分级的位置隐私保护。

Design of blockchain based zero-knowledge proof of location system

With the development of precise positioning technology,a growing number of location-based services(LBS)emerge.For example,visit a specific place to get the corresponding reward.This also leads to location fraud by illegal users in order to gain benefits.Thus,it is necessary to verify location certificates provided by users.However,present proof of location systems are deficient in verifying users’location certificates while protecting users’privacy.Users do not flexibly control their location certificates either.Based on blockchain,a kind of distributed proof of location system architecture was proposed and based on the proposed system architecture,a kind of proof of location protocol with zero-knowledge proof was proposed further.With the proposed architecture and the protocol,the proposed proof of location system allows users to freely select disclosed certificate parameters and positional accuracy according to their needs so that hierarchical location privacy protection was achieved.