Improvement of Dependability against Node Capture Attacks for Wireless Sensor Networks

A Wireless Sensor Network has sensor nodes which have limited computational power and memory size. Due to the nature of the network, the data is vulnerable to attacks. Thus, maintaining confidentiality is an important issue. To compensate for this problem, there are many countermeasures which utilize common or public key cryptosystems that have been proposed. However, these methods have problems with establishing keys between the source and the destination nodes. When these two nodes try to establish new keys, they must exchange information several times. Also, the routes of the Wireless Sensor Networks can change frequently due to an unstable wireless connection and batteries running out on sensor nodes. These problems of security and failure become more serious as the number of nodes in the network increases. In this paper, we propose a new data distribution method to compensate for vulnerability and failure based on the Secret Sharing Scheme. In addition, we will confirm the effect of our method through experiments. Concerning security, we compare our method with the existing TinySec, which is the major security architecture of Wireless Sensor Networks. key words: wireless sensor networks, security, node capture attack, secret sharing scheme, key refreshment