RFC 9858 · INFORMATIONAL · 2025

Additional Parameter Sets for HSS/LMS Hash-Based Signatures

Overview

RFC 9858, “Additional Parameter Sets for HSS/LMS Hash-Based Signatures”, is an Informational document published in October 2025 by S. Fluhrer, Q. Dang. The canonical text is published by the RFC Editor.

Abstract

This document extends HSS/LMS (RFC 8554) by defining parameter sets that use alternative hash functions. These include hash functions that result in signatures with significantly smaller sizes than the signatures that use the RFC 8554 parameter sets and should have sufficient security.

This document is a product of the Internet Research Task Force (IRTF). The IRTF publishes the results of Internet-related research and development activities. These results might not be suitable for deployment. This RFC represents the consensus of the Crypto Forum Research Group of the Internet Research Task Force (IRTF). Documents approved for publication by the IRSG are not candidates for any level of Internet Standard; see Section 2 of RFC 7841.

Abstract as published in the RFC, via rfc-editor.org.

What “Informational” means

Published for the general information of the community. It does not define an IETF standard and carries no standards-track status.

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