一种基于P2P网络技术的复合知识云模型

为了支持信息量和用户数均规模庞大的网络知识共享系统,必须采用先进的信息技术,云计算技术是理想的选择,但是仅采用云计算技术来构建知识共享系统还存在着一系列问题。文中将对等网络和云计算技术应用于大规模网络知识共享系统,提出了一种基于对等网络技术的复合知识云模型。模型本着平等、协作、分享、自由的互联网精神,并利用对等网络技术所推崇的"节点对等"思想,所有人不但共同贡献智慧和知识来协作编写百科全书,还充分调动互联网所有用户的力量,共同贡献各个用户计算机上的计算、存储资源和各种数据、软件等信息资源。基于该模型可以构建一种比现有的各种网络百科全书更为灵活、更为可靠、资源共享更为广泛的知识信息资源共享平台。文中还详细描述了基于对等网络技术的复合知识云模型MKCM(Multiplex Knowledge Cloud Model)的体系结构和工作流程,并深入探索了复合知识云模型的知识评价机制,对知识的价值进行有效的评价,从而选择最有价值的知识数据备份至服务器端以提高系统的整体性能

virus vaccine distribution algorithm based on hdht for large-scale networks

目前,反病毒系统防御病毒的主要方法是依靠反病毒中心服务器定期更新各个节点上的病毒定义文件和安装系统补丁,这种被动应对策略常常不够及时,且容易使服务器节点成为系统的性能瓶颈,具有较大的滞后性,也不能适应大规模网络系统。针对大规模网络环境提出了一种高效的基于层次式分布散列表(hierarchicaldistributed Hash table,HDHT)的反病毒疫苗分发算法。算法基于一种新型层次式分布散列表网络拓扑结构HDHT,利用网络边缘节点直接通信来提高病毒疫苗分发效率,从而有效分担服务器负载。为了增强算法的性能,算法还引入一种简洁的节点信誉评估机制。从分发效率、系统开销等方面,对病毒疫苗分发算法的性能进行实验验证和性能分析。结论表明,该算法可有效实现病毒疫苗在网络中快速分发和部署,同时减轻了网络和服务器的负载。国家自然科学基金(60873231)|高等学校博士学科点专项科研基金(20093223120001,20113223110003)|江苏省自然科学基金(BK2011754,BK2009426)|中国博士后科学基金(2011M500095)|江苏省博士后科研资助计划项目(1102103C)|江苏省科技支撑计划(BE2009158)|信息安全国家重点实验室开放课题(03-01-1)资助课题In order to defend viruses, current anti-virus systems usually deploy central servers to update virus definition files and install system patches on each client node regularly. This kind of passive strategy is often not timely, and the central server is easy to be the performance bottleneck of the system, which is obviously not suitable for large-scale networks. An efficient virus vaccine distribution algorithm based on hierarchical distributed Hash table (HDHT) for large-scale networks is proposed. HDHT is one of our research results, which is a novel HDHT network topology. The algorithm utilizes the direct communication between network edge nodes to speed up the vaccine distribution, which effectively shares server loads. In order to enhance the performance of the algorithm, a simple reputation evaluation mechanism is also introduced. Experimental results and performance analysis from the aspects of the distribution efficiency and system workloads show that the proposed vaccine distribution algorithm can reduce network and server loads with rapid distribution speed of vaccines

p2p incentive mechanism based on electronic coupons combined with global reputation values

为了解决对等计算(P2P)网络中存在的搭便车、公共悲剧、虚假文件、共谋以及不合作等问题,在分析对等节点类型和设定激励原则的基础上,提出了一种基于电子票券的P2P激励机制,并结合一种新的全局信誉度算法对节点行为进行调控.机制利用hash链技术并参考Payword思想设计了适用于P2P网络分布式支付行为的电子票券,并通过引入惩罚因子实现节点信誉度的评价方法.构建仿真实验环境对基于电子票券和全局信誉度的P2P激励机制展开了一系列实验.实验和分析结论表明,机制可有效遏制恶意节点,激励对等节点积极的、诚实地持续贡献自己的各种资源和进行协作,促使P2P网络逐渐演变为有序的任务协作和资源共享的运行环境.国家“九七三”计划项目(2011CB302903)|国家自然科学基金资助项目(60873231)|国家教育部高等学校博士学科点专项科研基金资助课题(20093223120001)|江苏省科技支撑计划项目(BE2009158)|江苏省自然科学基金资助项目(BK2011754、BK2009426)|江苏省高校自然科学研究项目(09KJB520010)|信息安全国家重点实验室开放课题(03-01-1)|江苏高校优势学科建设工程资助项目(yx002001)|中国博士后科学基金资助项目(2011M500095)In order to make up the deficiencies of free-riding, tragedy of the commons, fake-file, collusion and non-cooperation of peer to peer (P2P) networks, by analyzing the types of peers and setting the incentive principles, a new P2P incentive mechanism based on electronic coupons combined with a novel global reputation evaluation algorithm was proposed to regulate the behavior of peers. The mechanism utilized the hash chain and Payword technology to design the electronic coupon suitable for the distribution payment in P2P networks and also introduced the punishment factor to realize the peer's reputation evaluation algorithm. To verify the feasibility, the performance and the security of the mechanism, a series of experiments was implemented in the simulation environment. The results of experiment and analysis show that the mechanism can effectively curb the malicious nodes and stimulate peers to offer their resources and cooperation actively and honestly. Moreover, it could promote P2P networks to be harmonious and systematic computing environments able to support task collaboration and resource sharing

four-state passive propagation model of malicious code in p2p networks

对等网络的恶意代码传播和破坏问题日益严重。区分了对等网络中恶意代码的主动传播和被动传播2种情况,针对对等网络中被动传播的恶意代码提出了一种4状态被动传播模型4SPP。该模型根据对等点受恶意代码的影响状态,将对等点分为易感染对等点、已暴露对等点、已感染对等点和已免疫对等点4种类型,并给出了以微分方程表示的处于各种状态的对等点数量随时间迁移变化的规律公式。特别针对模型中的感染与免疫参数以及已感染对等点与已暴露对等点数量初始值的不同情况进行了仿真实验,直观地掌握对等网络恶意代码的基本被动传播规律,得出对抗P2P网络恶意代码的合理策略。国家自然科学基金资助项目(60873231)|国家973计划资助项目(2011CB302903)|中国博士后科学基金资助项目(2011M500095)|高等学校博士学科点专项科研基金资助项目(20093223120001)|信息安全国家重点实验室开放课题(03-01-1)|江苏省自然科学基金资助项目(BK2011754,BK2009426)|江苏省科技支撑计划资助项目(BE2009158)|江苏省普通高校自然科学研究资助项目(09KJB520010)|江苏省高校优势学科建设工程资助项目(YX002001)The propagation and attack of malicious codes in Peer-to-Peer networks (P2P) is getting more and more serious. The propagation of malicious code was divide into two types, passive and active propagations, and then a novel four-state passive propagation (4SPP) model of malicious code in P2P networks proposed. The model divides peers into four types, including susceptible peers, exposed peers, infected peers and healed peers, based on situation of peers infected by malicious codes. The differential equations showing how the numbers of peers in the various states migrating over time were also provided. The experiment results about the parameters of the model and two initial values of the number of infected peer and the number of exposed peer in different situations were presented, and the basic passive propagation law of malicious code in P2P network was obtained

mobile agent-based secure task partitioning and allocation algorithm for cloud & client computing

为了保障云端计算环境中任务的计算私密性,防止恶意节点或竞争对手窥探任务的内部逻辑及实现目标,提出一种新颖的基于移动Agent的云端计算安全任务分割与分配算法.算法同时考虑集群服务器节点和用户终端节点的计算能力与各自特点,将任务合理地切分为若干子任务,采用移动Agent来携带子任务的代码和数据部署到适当的任务执行节点上执行.结合实验原型系统对该算法进行性能分析,结果表明其可有效地保障执行子任务的终端节点,即使窥探到分配给它的代码和数据,甚至协同攻击系统,也无法了解该任务的整体执行逻辑和总体目标等.国家“九七三”计划项目(2011CB302903)|国家自然科学基金资助项目(60873231)|国家教育部高等学校博士学科点专项科研基金资助课题(20093223120001)|江苏省科技支撑计划基金资助项目(BE2009158)|江苏省普通高校自然科学研究基金资助项目(09KJB520010)|国家教育部科技发展中心基金资助项目(2009117)|信息安全国家重点实验室开放课题(03-01-1)In order to protect the privacy of the task in the cloud & client computing environment and prevent the malicious nodes or the competitors from prying into the internal logic and objectives of the task, a mobile Agent-based secure task partitioning and allocation algorithm for cloud & client computing is proposed. The new algorithm takes into account the cloud computing cluster server nodes and user terminals nodes together, divides task into a number of appropriate sub-tasks, and utilizes mobile Agent to carry the code and data of sub-tasks to the suitable nodes in accordance with the corresponding task allocation for implementation. The result of developed prototype system shows that, under the protection of the algorithm, the malicious terminal node looking into the code and data of the sub-task assigned to it or even co-attacking the system still can not understand the overall workflow and final objective of the task

一种对等网络主动型恶意代码与免疫疫苗的对抗传播模型

对等网络中主动型恶意代码通过主动扫描发掘漏洞，利用P2P 网络拓扑及其交互渠道自主扩散蔓 延整个网络，达到迅速破坏、瓦解、控制系统的目的。控制P2P 网络恶意代码的传播关键在于使得P2P 网 络中的节点能迅速获得疫苗的免疫。首先将P2P 网络中的恶意代码细分为主动和被动这两种类型，通过深 入分析P2P 网络中的主动型恶意代码的传播规律，提出一种适合与对等网络计算环境的主动型恶意代码与 免疫疫苗的对抗传播模型，模型根据Peer 节点受主动型恶意代码和免疫疫苗的影响情况细分为易感染、已 感染、已免疫和失效这四种典型状态，然后深入阐述节点状态的转换规律。对所提出对抗传播模型及其相 关参数展开细致的仿真实验，所得出的实验结果验证了本文提出的模型的正确合理性，为设计合理的P2P 网络节点免疫策略和高效的疫苗分发算法提供了科学的依据和合理的参考。中国电子学会 解放军信息工程大学 电子科技大