BitTorrent假块污染攻击的对抗方法研究  

Study on the Countermeasures of BitTorrent Fake Block Attack

作　　者：史建焘[1] 张宏莉[1] 方滨兴[1,2] 

机构地区：[1]哈尔滨工业大学计算机网络信息安全研究中心,哈尔滨150001 [2]中国科学院计算技术研究所信息安全研究中心,北京100190

出　　处：《计算机学报》2011年第1期15-24,共10页Chinese Journal of Computers

基　　金：国家"九七三"重点基础研究发展规划项目基金(2007CB311101);国家"八六三"高技术研究发展计划项目基金(2007AA010503;2009AA01Z437)资助

摘　　要：作为当前最为流行的P2P文件共享系统,BitTorrent容易受到假块污染攻击的威胁.文中剖析了假块污染攻击的攻击原理,通过建立简化的系统随机模型得出了攻击效果所能达到的理论上限,分析了影响攻击效果的主要因素,并通过仿真实验和广域网实验进行了攻击可行性的验证,比较了在不同攻击条件下的攻击效果.最后给出了针对块污染攻击的对抗方法,通过基于双Hash值的Smart Hash算法来改进BitTorrent的内容完整性校验协议,仿真实验表明该方法在对抗块污染攻击时是可行和有效的.Fake block attack is one of the most serious threats to the security and integrity of the BitTorrent network which is a very famous peer-to-peer file sharing system. Through using a mathematic model, this paper systematically analyzes the key factors to effect the result of fake block attack and gives a novel countermeasure against this security threat. Fake block attack aims to prolong the downloading time of the target file at victim peers by wasting their download band- widths and then to significantly damage the dissemination services of the whole target resource sharing swarm. Simulation and real world experiments prove the feasibility of fake block attack. This paper gives a stochastic model of the BitTorrent system with the impact of fake block at- tack, and calculates the theoretical upper bound of the result of fake block attack under the given circumstances. Finally this paper gives a two Hash value based SmartHash algorithm to enhance the robustness of BitTorrent content integrity checking progress and to counter against fake block attack. The simulation result shows that this method can effectively fight the threat of this attack.

关 键 词：网络安全 对等网 BITTORRENT 块污染 随机模型 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]