This paper presents the design and implementation of an integrated architecture for key exchange and authentication in wireless sensor networks (WSNs) employing elliptic curve cryptography (ECC) for key management. Instead of implementing a standard algorithm such as SHA or AES for authentication, this paper considers an elliptic curve based message authentication code (MAC) for optimized design of overall structure through hardware reuse. The proposed architecture time shares the point multiplication unit between functionalities of key exchange and MAC there by reducing the structural complexity. The proposed architecture is implemented over GF(2 163 ) on a Kintex 7 FPGA board using Xilinx ISE. The EC point multiplication is done using Lopez-Dahab algorithm and the finite field elements are represented using Gaussian normal basis to reduce the computational complexity and resist side channel attack.

Abstract