SHSlib

The Rambus SHSlib is a standalone stateful hash-based signatures software library, which provides signature verification for stateful hash-based signatures.

SHSlib implements SHA-256 operation in software and has hardware integration with the Rambus EIP-120. In addition, it can be integrated with another hardware SHA core for acceleration.

The library is optimized for minimal footprint and stack usage, and it is designed to be hardware and OS agnostic.

Features

• Fast and minimal LMS and XMSS software library
• Bare-metal, no OS nor HW dependencies
• Hardware acceleration option for SHA-256
• Single API for both HW and SW
• Support for integrating third-party SW or HW SHA-256 implementation
• Written in clear, highly portable C source code
• Engineer-level support and regular updates provided under maintenance

Specifications

• RFC 8391: XMSS: eXtended Merkle Signature Scheme
• RFC 8554: LMS: Leighton-Micali Hash-Based Signatures
• NIST SP 800-208 – Recommendation for Stateful Hash-Based Signature Schemes
• RFC 6234: US Secure Hash Algorithms (SHA and SHA-based HMAC and HKDF)

Supported Parameter Sets:

LMS:

• LMS_SHA256_M32_H10
• LMS_SHA256_M32_H15
• LMS_SHA256_M32_H20
• LMOTS_SHA256_N32_W4

XMSS:

• XMSS-SHA2_10_256
• XMSS-SHA2_16_256
• XMSS-SHA2_20_256

Use Cases

• Secure boot
• Firmware update
• No OS, resource constrained environment
• Quantum Safe requirements for above