Efficient implementation of EC based key management scheme on FPGA for WSN

Communication driven era demands the use of new cryptographic protocols and hardware with reduced computational and structural complexity for resource constrained applications. This paper presents the hardware implementation of a key management scheme based on Elliptic Curve Cryptography (ECC) for applications in wireless sensor networks. Security-critical applications in WSNs rely on ECC for the key management since it offers increased security per bit of the key. This paper proposes efficient hardware architecture for the implementation of EC based key exchange in such a way that number of pre-stored values for key exchange and overall hardware complexity of the system are optimised without affecting security level. Algorithms for pseudo random sequence generation and message authentication code based on cryptographic one way function of elliptic curve point multiplication are developed. A single point multiplication unit based on Lopez-Dahab algorithm is time shared for pseudo random sequence generation and authentication to reduce the overall hardware complexity. Thus the proposed implementation scheme supports increased number of node addition phases. Evaluation of the design is done in terms of storage and hardware complexity. Proposed system gives 23.76% hardware efficiency over the existing EC based system. The design for GF(2163) has been simulated in ModelSim PE 10.4, synthesized in Xilinx ISE 14.7 and successfully implemented on Kintex-7 KC705 Evaluation Board.