比特币POW机理研究及其在散列函数分析中的应用

项目名称： 比特币POW机理研究及其在散列函数分析中的应用

项目编号： No.61472476

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 自动化技术、计算机技术

项目作者： 谢涛

作者单位： 中国人民解放军国防科技大学

项目金额： 62万元

中文摘要： 比特币具有分布式去中心、匿名、免费、安全及通用等优点，近几年获得了快速发展，模仿比特币POW机理的密码货币竞相推出。针对51%攻击以及维护全网运行日益增长的巨大能耗问题，本课题提出构建公平绿色的POW机制，从技术上使ASIC矿机不再有利；提出利用比特币系统实现散列函数差分碰撞攻击的POW机制。主要内容包括：1）研究基于随机幻方演化算法POW过滤机制，消除蛮力搜索的技术条件；2）研究幻方演化算法的均匀随机性，设计线性POW难度调节方案，使比特币系统仅依靠网络CPU运算维持，消除51%攻击的技术条件；3）研究利用比特币系统免费解决sha1差分碰撞问题的POW机制，在维护系统正常运行前提下顺便解决密码分析问题；4）研究问题求解与比特币系统正常运行之间的平稳转换机制以及实时POW难度调节方案，使问题求解不至影响系统正常运行。本课题旨在解决比特币系统的公平性与环保性，提高互联网能源利用效率。

中文关键词： 数字密码货币；POW工作证明机制；智能计算；随机幻方构造；差分碰撞攻击

英文摘要： Characterized by distributed decentralization,anonymity,free transaction taxing,security and general-purpose application, bitcoin system has developed very fast in very recent years, quite a lot of new bitcoin inspired cryptographic currencies have been proposed. Considering the 51% attack problem and the everyday increasing huge energy consumption of the bitcoin system, this project raises a propose of building a fair and energy-saving POW scheme so that the ASIC based mining pools will be no longer in force, and proposes a scheme to exploit the huge computation capability to launch a practical collision attack on some cryptographic hash functions. Main topics include:1)A random magic square evolutionary algorithm is used to filter the work of POW scheme to eliminate the technical premise of the ASIC based brute force search;2)Study the stochastic distribution of magic square generation of the evolutionary algorithm in order to devise a linearized POW difficulty regulation scheme,so that the bitcoin system is only supported by internet networked computer's cpus;3)Try to design a POW scheme to exploit the bitcoin system in the differential collision attack on sha1 algorithm, such that a cryptanalysis can be freely accomplished without breaking the system running; 4)Try to devise a smooth transition scheme between the problem solving period and the normal running period of the bitcoin system,such that the problem solving will not collapse the running bitcoin system. This project is conducted to find a solution to the fairness and energy saving problem of the bitcoin system, so as to improve the energy utilization efficiency of the whole Internet network.

英文关键词： cryptgraphic currency;POW scheme;intelligent computations;random magic square construction;differential collision attack