近年來，無線感測網路的快速成長以及其應用越來越廣泛，由於感測網路大多是透過無線的方式來傳送資料，使得其安全議題倍受重視。由於感測節點本身有著電池電力容量小、計算能力弱以及記憶體空間少等資源限制，傳統的非對稱式演算法計算量過於龐大，所以建置有效率的非對稱式密鑰配置與管理機制，是目前高度重視的議題。如何利用有限的資源來達到最好的通訊需求以及安全是本篇論文的主要目的。
目前多數論文所討論的隨機密鑰配置方式，都使用隨機的方式，使得任兩節點間密鑰的建立必須依賴機率而決定，在面臨網路分佈不均的時候，會增加密鑰建立的困難性。我們的研究是根據共享式密鑰的概念加以修改，並且使用循環式區塊設計與幾何理論特性的設計方式，保證網路中任兩個節點都能互相建立密鑰。接著透過區塊設計的特性，增加節點間通訊的resilience，提高我們的機制的可行性以及網路的安全性，並且此機制擁有不須計算的優點，非常適合運算能力較差的感測節點使用。
此研究中，強調網路中任一節點對間必定能夠建立密鑰的保證，以及不須計算的優點，使得密鑰預先配置系統更加實際。最後，我們透過分析以及模擬的方式來驗證機制的效能。

Applications in wireless sensor network has been widely used in daily life. Communication among sensor nodes is based on wireless transmission. Therefore, security issue in wireless sensor networks has attracted significant attention in recent years. The resource constraints of sensor nodes, such as limited battery power, weak computational capability and limited memory size, make key predistribution issue more challenging in sensor networks. Asymmetric cryptography is unsuitable for sensor network due to its high computation overhead. Hence, an efficient solution in such resource constrained network is highly desirable.
Most existing approaches of key predistribution are random approaches in which keying information is carried randomly before deployment. Key establishment between any two nodes depends on probability, so it is hard to establish key when the topology of the network is skewed. The notion of our research is inspired by the concept of the cyclic block design and geometrical theory. Different from the random approaches, the scheme we proposed guarantees that any pair of nodes in the network can establish a communication key regardless of the topology of the network. Furthermore, we also use the technique of block design to enhance the resilience of the network.
The scheme we proposed places emphasis on the guarantee of key establishment and the advantage without computation which make key predistribution system more practical. We verify the performance by analysis and discuss the future work in the end of the paper.

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