要密钥分配是无线传感器网络中极具挑战性的安全问题之一.目前提出的解决方法是采用密钥预分配策略,给每个节点分配多个密钥,如Eschenauer和Gligor提出的随机密钥预分配方案(R—KPS).随机密钥预分配方案没有利用节点的部署和位置信息,在许多应用场合中,部署和位置信息能被用于改善网络性能.在R—KPS中,每个节点有可能成为其它任何节点的邻居,所以节点必须从同一密钥池中选取密钥.如果能把网络划分为多个区域,则同一区域内和相邻区域间的节点更有可能成为邻居.文章提出一种利用已知区域信息的密钥预分配方案,相比随机密钥预分配方案,能提高网络的连通性,减小节点所需存储空间,并能增强网络抗攻击能力.最后利用上述区域信息提出一种不借助定位设备的节点定位算法,此算法实现简单,适用于定位精度要求不高的场合.
Key distribution is one of the most challenging security problems in wireless sensor networks, existing approaches to this problem are to assign more than one key to each node, such as the random key pre-distribution scheme(R-KPS) proposed by Eschenauer and Gligor. The random key pre-distribution scheme does not use any deployment and location information, but in many practical scenarios, certain deployment knowledge may be available and can improve the performance. In R-KPS every node should choose key chain from the same key pool because they are equally likely to be neighbors. However, if the network can be divided into several domains, nodes from specific domain are more likely to be neighbors of nodes from the same domain and those from nearby domains. In this paper, the authors propose a method to improve the random key pre-distribution scheme using a priori area deployment information. Comparison to random key pre-distribution scheme shows that the authors' approach can substantially improve a network's connectivity, reduce the amount of memory required and enhance the network resilience against node capture, Finally, a new node positioning algorithm is put forward which does not rely on any position finding equipments and only exploits the domain's location information. This algorithm is simple, being applicable to the situation where the positioning accuracy demand is not high.