| 摘要: |
| 文档安全性对于信息共享Peer-to-Peer(或P2P)系统而言是一项重要的性能指标,以P2P系统的文档安全性优化为目标.P2P系统的文档安全性主要取决于两方面的因素:其载体的安全性和文档相关机制的构造,如副本管理等.对于P2P这样高度自主的分布式系统而言,文档安全性的提高无法依赖于结点安全性的提高,而应依靠对文档相关机制的控制来实现.首先设计了一个对文档安全性敏感的查询协议,以该查询协议为基础,与文档相关的机制就可以形式化地表述为函数,而系统文档安全性的提高就转化为函数空间上的数学分析.基于函数分析的结果,设计了一套旨在提高文档真实性的副本管理算法集合.理论分析的结果表明:在理想情况下,该算法集合可达到文档真实性的优化.对于实际系统,经过大量的模拟实验结果验证,该算法集可以获得良好的效果,接近优化水平. |
| 关键词: P2P网络 文档真实性 查询协议 副本管理 信任 |
| DOI： |
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| 基金项目:Supported by the Scientific Research Foundation of Harbin Institute of Technology under Grant No.HIT 2002.74 (哈尔滨工业大学基金) |
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| P2P Authenticity Query and Replica Management Algorithm Based on Trust |
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LI Zhi-Jun,LIAO Ming-Hong
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| Abstract: |
| The characteristic that nodes can enlist into the network topology freely and independently makes mobile Ad hoc networks (MANET) widely used in various environments such as disaster rescue, battlefield and so on. In MANET, the routing mechanism should adapt rapidly to the frequently changed network topology and in the mean time economize valuable network resources with its best. The Optimized Link State Routing Protocol (OLSR) is an important MANET routing protocol in which the key technique is MultiPoint Relays (MPR). After introducing the OLSR protocol and its MPR technique, the shortcoming of presently used heuristic algorithm in finding the minimum MPR sets is revealed. Then the new algorithm based on genetic algorithm (GA) is presented, and the convergence of the algorithm is proved. A series of 4 genetic algorithms are further developed by adopting different GA strategies and simulated in many topologies that are created randomly. Analysis on simulating results shows that the genetic algorithms are feasible and applicable and the choice of heuristic strategies is advisable and appropriate. |
| Key words: OLSR (optimized link state routing protocol) MPR (multipoint relays) heuristic algorithm genetic algorithm mobile ad hoc network |
