以网络为媒介的匿名评价研究

本研究用实证的方法对前人的研究进行了验证,并做了一定的扩展。结果发现与可识别身份条件相比,完全匿名与单向匿名均使得评价的批判性增强,评价者关注点在评价内容上,但评价的认知涣散也增强。匿名评价效应的关键因素在于评价者身份的隐匿。     

Anonymous multipath routing protocol based on secret sharing in mobile ad hoc networks

Because the intrinsic characteristics of mobile ad hoc networks(MANETs) cause several vulnerabilities,anonymous routing protocols attract much more attention in secure mobile ad hoc networks for the purposes of security and privacy concerns.Until recently,lots of anonymous routing protocols have been proposed.However,most of them are single path or use one path at a time,and the multipath schemes can not thwart both the passive attacks and active attacks simultaneously.Thus an anonymous multipath routing protocol based on secret sharing is proposed.The protocol provides identity anonymity,location anonymity,data and traffic anonymity by employing cryptograph technology and secret sharing in MANET communication process.Meanwhile,a hash function is introduced to detect active attacks in the data transmission process.The protocol can effectively thwart various passive attacks and reduce the successful probability of active attacks(such as interception and physical destroy attacks).Simulation results show that the proposed scheme provides a reasonably good level of network security and performance.     

基于MPKCs可撤销匿名性的环签名方案

可撤销匿名性的环签名方案是一种允许多用户完全匿名签名的方案,并可追踪签名者的真实身份,迄今为止所有可撤销匿名性的环签名方案都基于传统密码体制.然而随着量子计算机的出现,传统密码体制的安全性受到威胁.多变量公钥密码体制(MPKCs)是一种高效的密码体制,并且有可能成为后量子时代安全的密码体制.提出了一个基于MPKCs可撤销匿名性的环签名方案,该方案满足无条件匿名性,在非适应性选择消息下满足不可伪造性,可撤销匿名性,且运算效率高.     

Atomic and efficient e-cash transaction protocol

Atomicity is necessary for reliable and secure electronic commerce transaction and to guarantee the participants' interests. An atomic and efficient e-cash (electronic cash) transaction protocol based on the classical e-cash scheme is presented. The delivery of digital goods is incorporated into the process of payment in the protocol. Apart from ensuring all three levels of atomicity, the novel protocol features high efficiency and practicability with unfavorable strong assumption removed. Furthermore, the proposed protocol provides non-repudiation proofs for any future disputes. At last, analysis of the atomicity and efficiency is illustrated.     

Tor系统的改进方案

本文提出一种新的Tor匿名系统,能够使Tor系统发送者和接受者的身份得到更高的保护。引入了Crowds系统群组的概念,通过在群组中匿名提高发送者的匿名性。同时引入了组播的方法,通过向一个群组发送消息提高接受者的匿名性。这种方法能够有效的抵抗流量分析,使得本地监听者和组播监听者无法得知发送者和接受者的身份信息,提高了Tor系统的安全性。     

一种基于身份的多级代理环签名方案

代理签名能够实现委托签名,环签名能够让签名者不泄露签名身份。根据两个环之间的联系,提出一种突破“一级”限制的多级代理环签名方案,验证者只能验证签名人和授权人所在的环,不能获知签名人和授权人的具体身份。理论分析证明该方案是安全的。     

Anonymity control in electronic check systems

0IntroductionDepending on the payment mechanism,electroniccash can be classified into three categories:coin-based,divisible-cash-based,and check-based system.In acheck system,whichis introducedfirstly by Chaum[1],aclient normally pays the price with a single check andre-ceives a refundforthe difference betweenthe check valueand the price.Acheckcan always be usedto payfor anyitemwhose price is lower than the check value,and thecost of payment does not depend uponthe amount paid.Although check …     

基于交互确认机制的公平电子现金交易协议研究

公平性是电子现金交易协议应满足的重要属性,信道不可靠和交易实体不诚实是破坏交易公平性的主要原因。针对于此,借鉴不可否认转换签名的思想,构建交互确认机制,并基于改进的CEMBS可验证算法,提出一种新的公平电子现金交易协议,并对协议属性进行分析。分析表明,该协议有效解决上述原因引起的交易不公平问题,在满足公平性和匿名性的同时,可有效避免交易的模糊状态。     

基于匿名广播加密的P2P社交网络隐私保护系统

针对已有的广播加密方案无法很好地对用户的隐私进行保护问题,提出了基于合数阶双线性群以及拉格朗日插值法的具有接收者匿名性的广播加密方案。并针对现有的P2P社交网络存在的隐私保护方面的不足,基于匿名广播加密方案构建了P2P社交网络隐私保护系统。在Android客户端设计与实现了关键算法及系统的功能模块,并对各模块进行了功能验证。验证结果表明该匿名广播加密算法在保证对用户数据进行分发同时,解决了已有P2P社交网络中依赖高代价匿名技术来对用户数据进行隐私保护或者用户权限的过度开放等问题,有效地保护了接收者的隐私性。     

Ad Hoc匿名路由算法中的本地修复机制研究

针对Ad Hoc网络匿名路由算法研究局限于路由发现过程的问题,该文探讨了路由维护过程。将本地路由修复机制引入到匿名路由中,提出了一种高效的修复算法。该算法能够在路由失效后通过局部发现,快速重建路由,极大地提高了路由算法的性能。理论分析说明了该算法的安全性。仿真表明:在引入本地修复后,路由算法的传输延迟在节点平均移动速度为20 m/s时下降13%,分组投递成功率提高1.5%,控制报文减少约15%;且节点移动速度越快,本地修复机制的优越性越明显。