A Fast and Efficient Key Agreement Scheme for Wireless Sensor NetworksFast and Efficient Key Agreement • December 25th, 2023
Abstract—The Blom’s scheme for key agreement between pairs of nodes requires exchange of a small amount of bits, uses simple computations, and also authenticates each other. This makes it attractive for use in Wireless Sensor Networks but, in its original form, it has limitations because of the contending requirements for large pairwise keys and limited memory in the nodes. Our implementation of the Blom’s scheme uses multiple keys, enabling it to derive large pairwise keys using the limited memory resources, while retaining all the desirable features of speed, compactness, and low energy usage. We implemented our scheme in a MICAz mote and present some experimental results on the memory, computation time, and energy requirements. We compared the performance with other public key cryptographic methods used in WSN. Our scheme, using 382 bytes of RAM, was able to compute 128-bits pairwise keys in times ranging from 34 ms to 1.9 s for networks with capture thresholds of 32 and about 2,000
