【作者】 谭振华；

【导师】 常桂然；

【作者基本信息】 东北大学 ， 计算机系统结构， 2009， 博士

【摘要】 P2P覆盖网络(peer-to-peer overlay networks)具有自组织和分布式的特点,能够充分利用Internet环境中的边缘实体进行大规模的协同计算和资源共享,近年来得以快速发展,在文件共享、搜索引擎、分布式存储、分布式计算等领域都有广泛的应用。从拓扑的角度划分,P2P网络可以分为非结构化P2P和结构化P2P。目前较为流行的是结构化P2P网络,也是第三代P2P网络。由于结构化P2P覆盖网络规模的不断增长,要求更高的网络路由性能。传统的结构化P2P路由算法一般通过O(logn)路由指针项获得O(logn)的路由长度,并且在节点加入和退出时带来O(logn)的网络抖动。如何利用更少的路由指针获得更长的路由长度以及降低网络抖动,是目前结构化P2P网络路由算法研究的热点。另外,由于对等端的开放性、对等性、随意性以及无监督性给P2P网络带来了许多亟待解决的安全问题,如恶意节点攻击、团队恶意欺骗、知识产权问题等。本文围绕结构化P2P网络路由算法和P2P安全相关技术两方面内容展开了深入研究,取得了如下创新性研究成果：(1)提出了一种新的结构化P2P覆盖网络路由算法CSSP。该路由算法采用全分布式的单环拓扑,设计了缓存节点、后继节点和动态超级节点,提出了节点的缓存策略、节点加入和离开的路由维护算法以及超级节点的分布式选举算法,保证了CSSP的自组织。仿真和分析证明了CSSP的正确性,相比传统路由算法,CSSP通过O(L+2)的路由指针可获得O(N)的路由长度,路由平均在O(2)跳内完成,具有快速路由、低抖动和高容错特性,是一种有效的路由算法。(2)提出了一种基于节点通信历史聚类的结构化P2P路由算法K-CSSP。该路由算法通过对节点通信历史的分布式存储来计算节点的稳定性,利用K-means算法按稳定性对节点进行聚类,将CSSP划分为K个具有稳定核心并相互连通的域,通过O(L+K)的路由维护开销获得O(N)的路由长度,路由在O(K)跳内完成。给出了K-CSSP的分布式聚类模型,设计了节点加入和离开时的路由维护算法以及聚簇中心的更新算法来保证K-CSSP的自组织。实验及分析表明K-CSSP设计正确,具有较快的聚类收敛速度和稳定的路由性能,拓扑具有高稳定性,是一种高效的路由算法。(3)提出了一种新的P2P分布式信任模型NBRTrust.在节点通信历史分布式存储基础上构造了节点局部信任度评价分布式存储网β-list,通过分布式计算节点信任评价行为的相关度,得到节点相关度加权的全局信任模型NBRTrust,用于评估节点的可信程度；定义了模型的数学表述和分布式计算方法,设计基于NBRTrust信任模型的P2P通信模型。仿真分析表明,相比传统的局部信任模型和全局信任模型,NBRTrust信任模型更客观,能够有效抵御单个恶意节点和团队恶意节点的欺骗行为,是一种有效的信任模型。(4)提出了一种基于生物特征的结构化P2P内容控制方法HFFCSC。通过获取使用者的人脸生物特征生成256位密钥及256位随机IV序列对P2P内容进行分布式加解密,并且设计了包含使用者人脸参数的P2P响应报文,利用人脸生物特征对P2P内容进行版权控制。实验和分析表明,HFFCSC是有效的P2P内容控制方法。更多还原

【Abstract】 Peer-to-Peer overlay network, which is self-organized and distributed, can make full use of the edge system entities in Internet-scale to construct large-scale cooperating and resource sharing environments. With fast development in recent years, the p2p technology is used widely in many application areas like file sharing, search engine, distributed storage, distributed computing and etc. The p2p network can be classified into unstructured p2p and structured p2p in terms of the topology, and the structured p2p network is the third generation p2p network and more popular used, while the unstructured p2p is the first and second generation.As the network scale increasing continuously, the structured p2p network requests more efficient routing performance, while the traditional structured p2p routing protocols using O (logn) routing fingers to get O (logn) routing path and spending O (logn) network churning. In order to improve the routing algorithm efficiency of the structured peer-to-peer overlay networks, using much less routing fingers to get longer routing path and reducing the network churning, the routing algorithms are studied hotly. Because of the openness, reciprocity, random and spontaneous joining of the nodes and the lack of centralized system management in the structured distributed p2p system, some urgent problems regarding the availability and security of p2p network remain to be solved, such as evil node attacking, team evils cheating, intellectual property rights in p2p and etc. This paper presents in-depth study on p2p routing algorithms and p2p security technologies for structured p2p network, and makes some creative research results as follows:(1) Presented a new routing algorithm of structured p2p overlay networks, called CSSP. This routing algorithm use single-circle topology with cache nodes, successor nodes and a super node. The CSSP can get O (N) routing path only use O (L+2) routing fingers, and the routing operations can finished in O (2) hops. Cache policy, routing maintenance algorithms for nodes’ joining and leaving and election algorithms for super node were presented to ensure the self-organization. Simulations and analysis showed that the CSSP is an efficient route algorithm with quickly routing speed, lower churning count and high fault-tolerance.(2) Presented a new routing algorithm K-CSSP of structured p2p overlay networks based on clustering the nodes’communication history. This routing algorithm computing the nodes’stability via storing the nodes’communication history distributed. The K-CSSP uses the K-means algorithm to cluster the CSSP nodes by the stabilities into K regions which inter-linked each other by steady kernel node, and it can get O (N) routing path only use O (L+K) routing fingers, and the routing operations can finished in O (K) hops. A distributed cluster model, routing maintenance algorithms for nodes’ joining and leaving and cluster-center node’s updating algorithm were presented to ensure the self-organization. Simulations and analysis prove the rightness and efficiency with fast cluster constringency, steady routing performance and topology.(3) Presented a new distributed p2p trust model NBRTrust. Constructed the distributed local trust degree appraising networkβ-list based on the distributed storage for the nodes’communication history, the NBRTrust trust model, which was proposed to quantify and evaluate the trustworthiness of nodes, was formed by global trust model with nodes’correlative similarity weighted which was distributed computed from theβ-list. A mathematical description and a distributed implementation were defined, and a p2p communication model based on the NBRTrust model was designed. Simulations and analysis proved the NBRTrust was more impersonality comparing with traditional local trust model and global trust model, and it can withstand simple evil node’s attacking and team evil nodes’cheating also. The NBRTrust is an efficient global trust model.(4) Presented a new content controlling method HFFCSC based on biometric for structured p2p overlay networks. The HFFCSC generated 256 bits key and 256 bits IV sequence by obtaining the user’s human-face feature to encrypting and decrypting the p2p content. A p2p response message was designed which including user’s human-face parameter, to control the copyright of shared files. Experiment and analysis prove the rightness, and the HFFCSC is a valid content controlling method for structured p2p overlay networks.更多还原