安全在現在無線感測器網路(WSN, wireless senor networks)環境底下一直是眾所討論的議題之一，由於WSN本身獨特資源限制，讓WSN安全上必須額外考量計算能力、儲存空間容量、無線通訊特性、有限電池電源…等，隨機金鑰預配(RKP, random key pre-distribution)即是為了實現在WSN上安全通訊而發展的金鑰分配中的一環，RKP的特徵在於兩個獨立的節點必須至少有一個共同的預設金鑰才能構成對稱金鑰(pair-wise key)進而進行安全通訊，然而節點分佈若處於鬆散的環境上，由於平均節點度數下降，鄰居數較低，整體網路的連結性會隨著RKP不容易建立對稱金鑰的關係而下降，本論文將以提升鬆散環境下整體網路連結性為出發點，延伸原本只考量單跳鄰居資訊的RKP-DE，從雙跳鄰居資訊的觀點，將RKP-DE流程反向、提出RKP-DEinverse，再合併RKP-DE和RKP-DEinverse，成為新的方法RKP-DEtwo_hop，試著證明並實驗我們可以有效提升整體網路的連結性。

Under the current environment of Wireless Senor Networks (WSN), security is always one of the topics that everyone discussed about. Because of the limitations of WSN’s unique resource, this results in the security of WSN needs to especially consider the calculating ability, memory capacity, characteristics of wireless communication, limited battery power supply, etc. Random key pre-distribution (RKP) is the one of the key distribution that is developed for the sake of safe communication of WSN, the characteristic of RKP is that there must have at least one common pre-distributed key in the two independent nodes in order to compose a pair-wise key, so that the safe communication can be carried out. However, if the nodes are distributed in the loose environment, the numbers of neighbors would be lower due to the decrease of average node degree. Then the connectivity of the entire network would decrease because it is not easy for the RKP to establish the pair-wise key. This paper would set the improvement of the entire network’s connectivity under the loose environment as the starting point to extend the RKP-DE that only considers one-hop neighbor information, and reverse the flow path of RKP-DE and propose RKP- DEinverse from the viewpoint of two-hop neighbor information. Then RKP-DE and RKP- DEinverse are merged and become a new method – RKP- DEtwo_hop, so as to try to prove that we can raise the connectivity of the whole network effectively.

Page i. 中文摘要
Page ii. Abstract
Page iii. Content
Page v. List of Figures
Page vi. List of Table
Page 1. Chapter 1 Introduction
Page 1. 1-1 Background
Page 2. 1-2 Key Agreement
Page 3. 1-3 Motivation
Page 7. Chapter 2 Relative Works
Page 7. 2-1 Random key pre-distribution and
Q-composite
Page 7. 2-2 Random key distribution –decoupling
Page 8. 2-2-1 Network decoupling
Page 9. 2-2-2 Design of RKP-DE
Page 10. 2-2-3 Dependency Elimination
Page 11. Chapter 3 Design of our scheme
Page 11. 3-1 RKP-DEinverse
Page 13. 3-2 The Relationship between RKP-DE and
RKP-DEinverse
Page 14. 3-3 RKP-DEtwo_hop
Page 15. 3-4 Performance Analysis
Page 16. 3-4-1 Probability formula
Page 17. 3-4-2 Derivation of the formula
Page 21.Chapter 4 Simulation and Result Analysis
Page 21. 4-1 Definition
Page 22. 4-2 Sensitivity of connectivity to node number
Page 26. 4-3 Sensitivity of connectivity to key chain size
Page 30.Chapter 5 Conclusion and Future work
Page 31.Reference

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