基于可信第三方的高效可分电子现金方案  

A Trustee-Based and Efficient Divisible E-Cash Scheme

作　　者：虞郁磊 董晓蕾[2] 曹珍富[2] 

机构地区：[1]上海交通大学计算机科学与工程系,上海200240 [2]华东师范大学上海市高可信计算重点实验室,上海200062

出　　处：《计算机研究与发展》2015年第10期2304-2312,共9页Journal of Computer Research and Development

基　　金：国家自然科学基金项目(61321064;61373154;61371083;61411146001)

摘　　要：可分电子系统满足用户购买价值为2l的电子现金,并能拆分成多块进行消费.在该系统中需要保证用户的匿名性,同时又能查找出那些存在恶意行为的用户.2015年,Canard提出了第1个在随机预言机和标准模型下安全且高效实用的方案.其中对于提现价值为2l的电子现金,其复杂度是指数级的(需要2l次配对操作).提现操作中需要的高计算量为处理大额电子现金留下了隐患,当金额达到220时,会给系统造成严重的负担;当金额达到230时,系统几乎处于崩溃状态.鉴于以上潜在的不足,在Canard的基础上,通过引入可信第三方,提出了一个基于可信第三方的高效电子现金方案,作为对Canard方案的改进版.在方案中,结合可信第三方,减少了公共参数的数量和零知识证明的次数.特别是在提现的操作上,其计算复杂度与l是成线性相关的,为解决大额电子现金问题提供了可能.Divisible e-cash systems allow users to purchase a coin of value 2l and spend it part by part.This system not only need to ensure the anonymity of users,but also can detect double-spending behavior from malicious user.In 2015,Canard presented the first efficient divisible e-cash system in both random oracle model and standard model.In the system,for the coin of value 2l,the deposit protocol involves up to 2l pairing operations.When the value of coin is big,the divisible e-cash system will face challenges.If the value is 220,the system will withstand huge computation pressure;if the value is 230,it will be a state of collapse.For these potential shortcomings,independent of the work of Canard,we propose a more efficient divisible system based on a trusted third-party,as an improved version of Canard’s system.In the scheme,we make use of a trusted third-party,and reduce the number of public parameters and the number of zero-knowledge proof.Especially in the deposit operation,the complexity of deposit protocol is a linear correlation with l,which provides the possibility for solving the problem of large electronic cash.

关 键 词：可分 电子现金系统 可信第三方 树结构 承诺 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]