Efficient Implementation of Elliptic Curve Cryptography on DSP for Underwater Sensor Networks

As emerging sensor networks are normally deployed in the field and thus vulnerable to many types of attacks, it is critical to implement cryptographic algorithms in sensor nodes to provide security services. Public-key algorithms, such as RSA and Elliptic Curve Cryptography (ECC), have been widely used for security purposes like digital signature and authentication. In resource-constrained sensor networks, ECC is more suitable than other public-key algorithms based on large integer fields because it provides similar security strength with shorter keys and thus is more computation-efficient. However, even ECC is slow on many sensor nodes. In underwater sensor networks (UWSNs), sensor nodes communicate with each other through acoustic channels. Because more complicated algorithms are needed to encode and decode acoustic signals transmitted through the noisy underwater channels, many acoustic modems include a DSP to meet the performance requirement of underwater communications. In this paper, we study the implementation of ECC on DSPs. We optimize the SECG elliptic curves secp160r1 and secp224r1 on a TMS320C6416 DSP board from Texas Instruments. In our implementation, it takes 0.81 ms to compute a random scalar point multiplication for secp160r1, an order of magnitude faster than the communication algorithm decoding a data block. Therefore, we believe that it is feasible to adopt ECC in UWSNs.