NIST Releases Lightweight Cryptography Standard for IoT Devices

USA: NIST Releases Lightweight Cryptography Standard for IoT Devices

A new lightweight cryptography standard designed for resource‑constrained devices has been finalized, aiming to bolster security across the expanding Internet of Things ecosystem. The National Institute of Standards and Technology (NIST) announced the release on August 13, 2025, with an update issued on August 18, 2025, to address the growing need for efficient encryption in miniature electronics.

Purpose and Scope

The standard targets data created and transmitted by billions of connected devices, including RFID tags, medical implants, and other small electronics that lack the computational power of traditional computers or smartphones. By providing a set of algorithms optimized for limited energy, time, and memory, the guidance seeks to make strong cryptographic protection feasible for these devices.

Algorithmic Foundations

All four variants are built on the Ascon family of algorithms, which NIST selected in 2023 after a multiround public review. Ascon was originally developed in 2014 by researchers from Graz University of Technology, Infineon Technologies, and Radboud University, and later emerged as the leading candidate in the CAESAR competition in 2019.

Key Variants

The publication, titled *Ascon‑Based Lightweight Cryptography Standards for Constrained Devices* (NIST Special Publication 800‑232), includes four algorithmic options. ASCON‑128 AEAD supports authenticated encryption, while ASCON‑Hash 256 provides a fixed‑size fingerprint for data integrity. The XOF variants, ASCON‑XOF 128 and ASCON‑CXOF 128, allow adjustable hash lengths, with the CXOF version also supporting a customizable label to mitigate collision risks.

Security Considerations

Designers emphasize that ASCON‑based algorithms are structured to facilitate side‑channel‑resistant implementations, addressing a common vulnerability in small devices where power consumption or timing can leak information. Although no algorithm is completely immune, the standard offers guidance to reduce such risks.

Potential Applications

According to NIST computer scientist Kerry McKay, the standard is expected to benefit industries that produce smart‑home appliances, car‑mounted toll transponders, and implanted medical devices. By fine‑tuning cryptographic overhead, manufacturers can maintain device performance while enhancing security.

Future Directions

McKay noted that the team intends the framework to be expandable, citing community feedback that may lead to additional functionalities such as a dedicated message authentication code. The agency plans to evaluate these possibilities in the near term.

This report is based on information from NIST, licensed under Public Domain (U.S. Government Work). Source: Official U.S. Government release.