【正文】 治，并使用無線通信的方式進行多跳轉(zhuǎn)發(fā)。關(guān)鍵詞：無線傳感器網(wǎng)絡(luò)，網(wǎng)絡(luò)安全，信任評估，層次路由63AbstractThe routing protocol for wireless sensor networks suffers from plicated security threats in practice. Sensor nodes are usually deployed in open, unattended or hostile areas. For the constraint of node resources and absence of tamperresistant infrastructure, they are vulnerable to physical capture by adversaries. Attackers can easily reprogram these promised nodes to launch harmful routing attacks, such as selective forwarding, denial of services, wormhole, sybile and sinkhole attack. In addition, the information asymmetry and uncertainty bee a challenging issue for secure routing design because of confidentiality of sensed data, instability of wireless channels, multihop transmission for data pcakets, selfish behaviors of individualized nodes, equipment malfunctions, environment changes and other factors. Trust evaluation framework can resolve the inner attack problem caused by node capture, and effectively account for the node failure problem. Consequently, it plays an important role in enhancing routing security and improving network performance.In order to establish credible and efficient data transmission environment, and smoothly execute the functions of network, it is necessary to make an indepth research in trust evaluation and hierarchical routing. Therefore, we mainly focus on the calculation and application of node trust value, and set up a secure routing mechanism based on trust evaluation. Through mutual observation and cooperation among neighbor nodes, evaluated subject nodes recognise and remove the malicious, selfish and failure nodes。仿真結(jié)果表明，該模型具有良好的動態(tài)性和魯棒性，能夠有效抵抗多種網(wǎng)絡(luò)攻擊，提高了網(wǎng)絡(luò)的安全性。仿真和實驗結(jié)果表明，該模型能夠簡單快速地評估節(jié)點間的信任值，有效識別惡意節(jié)點。為建立可靠高效的數(shù)據(jù)傳輸環(huán)境，順利實現(xiàn)網(wǎng)絡(luò)正常功能，迫切需要對信任評估和層次路由的關(guān)鍵技術(shù)進行深入研究。作者簽名： 日期： 年 月 日導(dǎo)師簽名： 日期： 年 月 日摘 要無線傳感器網(wǎng)絡(luò)（Wireless Sensor Networks，WSNs）路由協(xié)議面臨著復(fù)雜的安全威脅。本人完全意識到本聲明的法律后果由本人承擔(dān)。保密學(xué)位論文在解密后的使用授權(quán)同上。盡我所知，除文中已經(jīng)加以標注和致謝外，本論文不包含其他人已經(jīng)發(fā)表或撰寫的研究成果，也不包含本人或他人為獲得北京航空航天大學(xué)或其它教育機構(gòu)的學(xué)位或?qū)W歷證書而使用過的材料。與我一同工作的同志對研究所做的任何貢獻均已在論文中作出了明確的說明。學(xué)位論文作者簽名： 日期： 年 月 日指導(dǎo)教師簽名： 日期： 年 月 日學(xué)位論文原創(chuàng)性聲明本人鄭重聲明：所呈交的論文是本人在導(dǎo)師的指導(dǎo)下獨立進行研究所取得的研究成果。作者簽名： 日期： 年 月 日學(xué)位論文版權(quán)使用授權(quán)書本學(xué)位論文作者完全了解學(xué)校有關(guān)保留、使用學(xué)位論文的規(guī)定，同意學(xué)校保留并向國家有關(guān)部門或機構(gòu)送交論文的復(fù)印件和電子版，允許論文被查閱和借閱。傳感器節(jié)點通常隨機部署在開放、無人值守或惡劣的環(huán)境中，節(jié)點資源受限，缺乏必要的安全措施，較容易被攻擊者捕獲，改造成惡意節(jié)點，對路由層發(fā)動選擇性轉(zhuǎn)發(fā)攻擊、拒絕服務(wù)攻擊、蠕蟲洞攻擊、女巫攻擊、陷洞攻擊等。因此，論文以節(jié)點信任值的計算和應(yīng)用為核心，建立了一套基于節(jié)點信任評估的安全路由機制：通過鄰居節(jié)點間的相互觀測和協(xié)作，評估主體識別并排除惡意節(jié)點、自私節(jié)點和故障節(jié)點；在節(jié)點安全可信的基礎(chǔ)上，建立層次路由協(xié)議。該模型主要采用比值和加權(quán)平均方法，算法復(fù)雜度較低，符合無線傳感器網(wǎng)絡(luò)內(nèi)存、計算能力和能量有限的特點。三、在上述工作基礎(chǔ)上，提出了一種基于節(jié)點信任值的無線傳感器網(wǎng)絡(luò)層次路由協(xié)議HRBNT。 on the basis of node trust, the hierarchical routing is pleted.The research is divided into three parts:To counteract specific attacks in wireless sensor networks, a trust evaluation model based on probability statistics and singlevalued logic is proposed. Considering the munication station, data content and residual energy, a group of trust factors were defined. The direct trust value is puted by weighted average, and the remendation trust value is obtained through simple remendation protocol. The experiment and simulation results prove that the proposed model can simply and fleetly evaluate the trust value, and availably identify the malicious node. Because it mainly uses the ration approach and average method, the plex degree of the proposed model is low, which suits the characteristic of limited memory, pute ability and energy for wireless sensor network. For the uncertainty, fuzziness and subjectivity of trust, a trust evaluation model based on evidence theory and multiplevalued logic is proposed. Firstly, according to a group of monitored trust factors, the subject node uses the fuzzy logic method to pute the basic confidence level, which is bined with local history records and correlation of time context to evaluate direct trust values on neighbor nodes. Then, in order to obtain the remended trust values from third part nodes, conditional transitivity and dynamic aggregation progress of trust values are developed. Finally, according to DS evidence theory, the overall trust value is calculated by synthesizing the direct and remended trust values. Meanwhile, it is indicated by simulation results that the proposed model has excellent dynamic characteristic, robustness and ability to deal with various network attacks. Therefore, the network security is enhanced.A hierarchical routing algorithm based on node trust value named HRBNT is put forward to enhance the routing security during the data transmission in wireless sensor networks. The node trust value is bined with the density and distance among nodes to select backbone nodes in network. Then, the local trust value is employed to exclude the malicious nodes and establish a reliable hierarchical route. Experiment results show that the proposed algorithm can effectively prevent low trust nodes from transferring data packets. Furthermore, the security problem of hierarchical route caused by node failure or capture is also settled.Keywords: Wireless sensor networks, Network security, Trust evaluation, Hierarchical routing目 錄第一章 緒論 1 課題背景及意義 1 無線傳感器網(wǎng)絡(luò)體系結(jié)構(gòu) 2 無線傳感器網(wǎng)絡(luò)概述 2 無線傳感器網(wǎng)絡(luò)節(jié)點結(jié)構(gòu) 3 無線傳感器網(wǎng)絡(luò)協(xié)議棧 4 無線傳感器網(wǎng)絡(luò)路由協(xié)議 5 無線傳感器網(wǎng)絡(luò)路由協(xié)議的特點 5 無線傳感器網(wǎng)絡(luò)路由協(xié)議的設(shè)計 6 無線傳感器網(wǎng)絡(luò)路由協(xié)議的分類 6 無線傳感器網(wǎng)絡(luò)信任評估機制 7 信任的基本概念 7 無線傳感器網(wǎng)絡(luò)信任評估框架 8 國內(nèi)外研究現(xiàn)狀 10 論文內(nèi)容及整體結(jié)構(gòu) 12第二章 基于概率統(tǒng)計的單值信任評估模型 14 引言 14 無線傳感器網(wǎng)絡(luò)中常見的攻擊形式 14 分布式信任評估機制 16 信任因子的定義 17 信任值的計算 19 直接信任值的計算 19 簡單信任推薦協(xié)議 20 推薦信任值及總體信任值的計算 20 仿真分析 21 實驗驗證 24 小結(jié) 27第三章 基于證據(jù)理論的多值信任評估模型 28 引言 28 證據(jù)理論的基本概念 28 信任值的形式化定義 29 直接信任值的計算 29 推薦信任值的計算 31 推薦節(jié)點的確定 32 信任值的條件傳遞 33 總體信任值的合成 37 仿真實驗 38 動態(tài)性分析 38 魯棒性分析 39 小結(jié) 41第四章 基于節(jié)點信任值的無線傳感器網(wǎng)絡(luò)層次路由 42 簇頭節(jié)點的可信選舉 42 層次路由 44 HRBNT算法的具體過程 44 閾值T(n)的確定 46 仿真分析 48 簇頭節(jié)點的可信選舉 49 層次路由的建立 50 小結(jié) 52第五章 總結(jié)與展望 53 工作總結(jié) 53 未來展望 54參考文獻 55攻讀碩士學(xué)位期間取得的成果 59致謝 60北京航空航天大學(xué)碩士學(xué)位