SPHINCS+
The SPHINCS+ reference code accompanying the NIST submission, placed in the public domain by its authors.
Why this is listed
The submission software is the repository's entire content, placed in the public domain and offered under CC0-1.0, the BSD Zero Clause Licence and MIT, so anyone can read and reuse it.
The repository states that it contains the software accompanying the SPHINCS+ submission to NIST's post-quantum cryptography project. It documents 36 named instances targeting NIST security categories 1, 3 and 5, split between parameter sets tuned for compact signatures and parameter sets tuned for faster signing.
The code is placed in the public domain and offered under CC0-1.0, the BSD Zero Clause Licence and MIT No Attribution. The front page does not use the name SLH-DSA or cite FIPS 205, so this entry does not claim it does; that mapping is stated by the standard rather than by the repository.
Sources
Checked against these sources on Sep 4, 2026. Listing is not endorsement, and nothing here is ranked or scored.