Session Key Derivation for Low Power IoT Devices

Abstract

The Internet of Things (IoT) is growing at a rapid pace. With everyday applications and services becoming wirelessly networked, security still is a major concern. Many of these sensors and devices have limited resources, such as low power consumption, reduced memory storage, and reduced fixed point processing capabilities. Therefore, it is imperative that high performance security primitives are used to maximize the lifetime of these devices while minimally impacting memory storage and timing requirements. This paper presents a candidate key derivation function for low power IoT device keys, enabling the generation of a stream of session keys from a larger base key. These session keys allow for a reasonably robust private key cryptographic infrastructure suitable to low power reduced precision systems. Two methods are examined to ensure that the output for the key derivation function is reasonably indistinguishable from a uniform distribution and produces good keys. Simulations show that all methods show favorable outcomes and allow the derivation of variable length keys suitable for many different encryption schemes. Implementation resulted in very favorable energy consumption values for low power performance, ideal for IoT devices.