Several algorithms are proposed which uses the basic scheme by predistributing random keys into nodes. The drawback is that one pair wise key may be shared by multiple links. Chan et al. presented two schemes. In their q-composite scheme, multiple keys are required to establish a secure link, which makes a trade-off between connectivity and security. In their random pair wise-key scheme, a unique pair wise key is assigned to each node and every one of a random set. This scheme provides high security but poses an upper bound on network size. Du et al. proposed the pair wise key predistribution scheme based on both the basic scheme and Blom’s scheme, from which it inherits the threshold property. On the contrary, our scheme utilizes Blom’s scheme more smoothly.

Wireless, Authentication, Sensor network, Trust management

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[11] utilizing probabilistic key predistribution, which was improved byChanet al. And Duet al. Recently, Duet al.And Liu and Ning independently proposed to make use of deployment knowledge to further improve the performance of key establishment. Different from all these schemes, LEAP proposed by Zhu et al. assumes a weaker model, that is, there exists a short time interval within which nodes can establish pair wise keys safely after deployment.