SeGrid: A Secure Grid Infrastructure for Sensor Networks

In this paper, we propose SeGrid, a secure grid infrastructure for large scale sensor networks. The basic idea relies on the availability of a low-cost public cryptsystem (e.g. Blom’s key management scheme [4]) that can be used for shared key computation between the source and the destination, as long as the public shares are known to each other. In SeGrid, each sensor resides in a grid computed from its physical location. Within a grid, one or a few number of sensors, with one of them the grid head, are active at any instant of time and all other sensors fall asleep for energy conservation. We intend to compute a shared key for two grids instead of two nodes, such that the grid heads can securely communicate with each other. The public shares of a grid are stored at designated locations based on our public share management protocol such that the closer two grids, the shorter distance to obtain each other’s public shares. We instantiate SeGrid based on Blom’s key management scheme [4] to illustrate the computation of a grid key. To our best knowledge, this is the first work that simultaneously considers both key management and network lifetime extension, which explores along the dimension of network density.