# Hash Functions and Benchmarks for Resource Constrained Passive Devices: A Preliminary Study

## TL;DR

This paper examines hash functions suitable for resource-constrained, intermittently powered IoT devices, providing benchmarks and an execution model to address security challenges in such energy-limited environments.

## Contribution

It evaluates lightweight hash primitives on low-power devices and proposes an execution model for intermittent powering scenarios, addressing a gap in security solutions for energy-constrained IoT devices.

## Key findings

- Benchmarks for eight hash primitives on low-power devices
- Analysis of hash function performance under intermittent power
- Outline of an execution model for security primitives in energy-limited IoT

## Abstract

Recently, we have witnessed the emergence of intermittently powered computational devices, an early example is the Intel WISP (Wireless Identification and Sensing Platform). How we engineer basic security services to realize mutual authentication, confidentiality and preserve privacy of information collected, stored and transmitted by, and establish the veracity of measurements taken from, such devices remain an open challenge; especially for batteryless and intermittently powered devices. While the cryptographic community has significantly progressed lightweight (in terms of area overhead) security primitives for low cost and power efficient hardware implementations, lightweight software implementations of security primitives for resource constrained devices are less investigated. Especially, the problem of providing security for intermittently powered computational devices is unexplored. In this paper, we illustrate the unique challenges posed by an emerging class of intermittently powered and energy constrained computational IoT devices for engineering security solutions. We focus on the construction and evaluation of a basic hash primitive---both existing cryptographic hash functions and non-cryptographic hash functions built upon lightweight block ciphers. We provide software implementation benchmarks for eight primitives on a low power and resource limited computational device, and outline an execution model for these primitives under intermittent powering.