IoT Key Exchange Performance Analysis.

The security of data, in motion and at rest, depends on the ability to exchange session keys between communicating parties. Key agreement approaches can provide the additional security assurance of perfect forward secrecy, however, for many Internet of Things resource-constrained devices the session key establishment process is too costly in terms of energy consumption and processing time. In this paper, we quantify the energy consumption and execution load when performing session key establishment. We develop a software security framework, implementing both lightweight key transport and key agreement, the latter based on elliptic curve Diffie-Hellman (ECDH). Measurements are taken using energy and digital-events monitoring tools. We find that key agreement implemented via software requires a quantity of energy thousand of times greater than a key transport approach. Also, we measure and quantify how much a hardware implementation can improve energy and execution time performance. Our research provides critical information for practitioners in selecting the appropriate hardware and security scheme for IoT applications.