Calculating a Cryptographic Primitive: Suitable for Wireless Sensor Networks

A sensor node in a wireless sensor network has a limited machine word size. This limitation restricts the use of cryptographic algorithms developed for computer networks in a wireless sensor node. Most of the modern cryptographic algorithms use the multiplicative inverse of a Galois field and therefore it is important to develop storage- and energy-efficient approaches for sensors to calculate multiplicative inverses. This paper presents two techniques to compute multiplicative inverses of a Galois field of order prime p for a wireless sensor network. The performance of the proposed algorithm is compared with that of the extended Euclid algorithm. The results show that the proposed approaches are storage-and energy-efficient, and are computationally better than the extended Euclid algorithm.