NIST releases lightweight cryptography standard for IoT devices

The National Institute of Standards and Technology (NIST) has finalised a lightweight cryptography standard aimed at safeguarding even the smallest networked devices from cyberattacks. Published as Ascon-Based Lightweight Cryptography Standards for Constrained Devices (NIST Special Publication 800-232), this standard provides essential tools for securing data generated and transmitted by billions of Internet of Things (IoT) devices, as well as other compact electronics like RFID tags and medical implants. These devices typically possess significantly less computing power than smartphones or laptops, yet they still require robust protection. Lightweight cryptography is specifically designed for these resource-constrained environments. NIST computer scientist Kerry McKay, who co-led the project with Meltem Sönmez Turan, emphasised the importance of this standard for industries developing devices ranging from smart home appliances to car-mounted toll registers and medical implants.

The standard is based on algorithms from the Ascon family, which were selected in 2023 following a comprehensive public review process. Originally developed in 2014 by researchers from Graz University of Technology, Infineon Technologies, and Radboud University, Ascon gained recognition in 2019 as the leading choice for lightweight encryption in the CAESAR competition, demonstrating its resilience through extensive cryptographic evaluation. The standard includes four Ascon variants tailored for different use cases, addressing two primary needs: authenticated encryption with associated data (AEAD) and hashing. ASCON-128 AEAD is designed for devices that need to encrypt data and verify its integrity, while ASCON-Hash 256 generates a short hash to serve as a data fingerprint. Additionally, ASCON-XOF 128 and ASCON-CXOF 128 offer flexible hash functions that can be adjusted for length, optimising time and energy consumption for small devices.