Consideration of efficient nearest node discovering mechanisms for key infection

Given the growing number of applications of wireless sensor networks, security has been focused on as an important issue. One of the important security issues in sensor networks is key agreement scheme. Several schemes have been proposed, but none of them satisfy the sensor network requirement absolutely due to the serious constrains of the sensor network. Key infection (R. Anderson et al., 2004) intends to solve this problem by introducing a new paradigm in key agreement scheme on sensor networks, which assumes a realistic attacker model. In the key infection model, it is important to discover nearest sensor node at the key agreement time for secrecy improving. In this paper, we suggest several mechanisms to discover nearest sensor node, which is named "key whispering" in the key infection model, and compare them with each other in terms of energy efficiency and secrecy.