想要在無線感測網路環境中達到安全目的，就必須要針對感測節點間所要傳送的訊息予以加密及認證；為了要達到這個目的，想要互相通訊的節點間勢必要能夠產生出所需的通訊密鑰以供加密及認證用；然而，由於感測節點先天上的硬體限制，想要在此環境中產生通訊所需的密鑰並不是那麼容易達成。目前已有許多密鑰產生的機制用於一般網路，例如Diffie-Hellman以及一些以公開金鑰基礎的機制，但是由於感測節點的計算能力有限，此類方法並不適用。
在這篇論文中，我們的研究的動機就是解決無線感測網路安全易於被破解的缺陷，進而發展出一套以法團(Quorum)為基礎的密鑰預先配置機制，再結合Blom的機制，企圖在有限記憶體下達到較好的安全通訊。相對於之前的研究，我們主要是利用法團的特性，以多個key spaces達成提升破解安全的所需compromised的節點的目的。

In order to achieve security in wireless sensor networks, it is very important to be able to encrypt and authenticate data sent between sensor nodes. Before doing that, secret keys used for encryption and authentication must be agreed upon by the communicating parties. However, due to resource constraint of the sensor nodes, it is not easy to achieve key agreement in WSNs. There are many key agreement schemes used in general network, such as Diffie-Hellman and other public-key based schemes, but they are not suitable for WSNs due to the limited computational abilities of the sensor nodes.
The objective of this paper is to enhance the security of a wireless sensor network by combining the notion of quorums and the Blom’s mechanism for key establishment. In contrast with previous works, our scheme uses multiple key spaces in an attempt to increase the number of sensor nodes that must be compromised before a connection is rendered unsafe. And, this is done under the constraint of limited memory size of a sensor node.

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