# SPHINCS+ - **Algorithm type**: Digital signature scheme. - **Main cryptographic assumption**: hash-based signatures. - **Principal submitters**: Andreas Hülsing. - **Auxiliary submitters**: Jean-Philippe Aumasson, Daniel J. Bernstein,, Ward Beullens, Christoph Dobraunig, Maria Eichlseder, Scott Fluhrer, Stefan-Lukas Gazdag, Panos Kampanakis, Stefan Kölbl, Tanja Lange, Martin M. Lauridsen, Florian Mendel, Ruben Niederhagen, Christian Rechberger, Joost Rijneveld, Peter Schwabe, Bas Westerbaan. - **Authors' website**: https://sphincs.org/ - **Specification version**: NIST Round 3 submission, v3.1 (June 10, 2022). - **Primary Source**: - **Source**: https://github.com/PQClean/PQClean/commit/1eacfdafc15ddc5d5759d0b85b4cef26627df181 with copy_from_upstream patches - **Implementation license (SPDX-Identifier)**: CC0-1.0 ## Advisories - This algorithm is not tested under Windows. ## Parameter set summary | Parameter set | Parameter set alias | Security model | Claimed NIST Level | Public key size (bytes) | Secret key size (bytes) | Signature size (bytes) | |:--------------------------:|:----------------------|:-----------------|---------------------:|--------------------------:|--------------------------:|-------------------------:| | SPHINCS+-SHA2-128f-simple | NA | EUF-CMA | 1 | 32 | 64 | 17088 | | SPHINCS+-SHA2-128s-simple | NA | EUF-CMA | 1 | 32 | 64 | 7856 | | SPHINCS+-SHA2-192f-simple | NA | EUF-CMA | 3 | 48 | 96 | 35664 | | SPHINCS+-SHA2-192s-simple | NA | EUF-CMA | 3 | 48 | 96 | 16224 | | SPHINCS+-SHA2-256f-simple | NA | EUF-CMA | 5 | 64 | 128 | 49856 | | SPHINCS+-SHA2-256s-simple | NA | EUF-CMA | 5 | 64 | 128 | 29792 | | SPHINCS+-SHAKE-128f-simple | NA | EUF-CMA | 1 | 32 | 64 | 17088 | | SPHINCS+-SHAKE-128s-simple | NA | EUF-CMA | 1 | 32 | 64 | 7856 | | SPHINCS+-SHAKE-192f-simple | NA | EUF-CMA | 3 | 48 | 96 | 35664 | | SPHINCS+-SHAKE-192s-simple | NA | EUF-CMA | 3 | 48 | 96 | 16224 | | SPHINCS+-SHAKE-256f-simple | NA | EUF-CMA | 5 | 64 | 128 | 49856 | | SPHINCS+-SHAKE-256s-simple | NA | EUF-CMA | 5 | 64 | 128 | 29792 | ## SPHINCS+-SHA2-128f-simple implementation characteristics | Implementation source | Identifier in upstream | Supported architecture(s) | Supported operating system(s) | CPU extension(s) used | No branching-on-secrets claimed? | No branching-on-secrets checked by valgrind? | Large stack usage?‡ | |:---------------------------------:|:-------------------------|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:----------------------| | [Primary Source](#primary-source) | clean | All | All | None | False | False | False | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2 | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ‡For an explanation of what this denotes, consult the [Explanation of Terms](#explanation-of-terms) section at the end of this file. ## SPHINCS+-SHA2-128s-simple implementation characteristics | Implementation source | Identifier in upstream | Supported architecture(s) | Supported operating system(s) | CPU extension(s) used | No branching-on-secrets claimed? | No branching-on-secrets checked by valgrind? | Large stack usage? | |:---------------------------------:|:-------------------------|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | [Primary Source](#primary-source) | clean | All | All | None | False | False | False | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2 | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## SPHINCS+-SHA2-192f-simple implementation characteristics | Implementation source | Identifier in upstream | Supported architecture(s) | Supported operating system(s) | CPU extension(s) used | No branching-on-secrets claimed? | No branching-on-secrets checked by valgrind? | Large stack usage? | |:---------------------------------:|:-------------------------|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | [Primary Source](#primary-source) | clean | All | All | None | False | False | False | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2 | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## SPHINCS+-SHA2-192s-simple implementation characteristics | Implementation source | Identifier in upstream | Supported architecture(s) | Supported operating system(s) | CPU extension(s) used | No branching-on-secrets claimed? | No branching-on-secrets checked by valgrind? | Large stack usage? | |:---------------------------------:|:-------------------------|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | [Primary Source](#primary-source) | clean | All | All | None | False | False | False | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2 | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## SPHINCS+-SHA2-256f-simple implementation characteristics | Implementation source | Identifier in upstream | Supported architecture(s) | Supported operating system(s) | CPU extension(s) used | No branching-on-secrets claimed? | No branching-on-secrets checked by valgrind? | Large stack usage? | |:---------------------------------:|:-------------------------|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | [Primary Source](#primary-source) | clean | All | All | None | False | False | False | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2 | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## SPHINCS+-SHA2-256s-simple implementation characteristics | Implementation source | Identifier in upstream | Supported architecture(s) | Supported operating system(s) | CPU extension(s) used | No branching-on-secrets claimed? | No branching-on-secrets checked by valgrind? | Large stack usage? | |:---------------------------------:|:-------------------------|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | [Primary Source](#primary-source) | clean | All | All | None | False | False | False | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2 | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## SPHINCS+-SHAKE-128f-simple implementation characteristics | Implementation source | Identifier in upstream | Supported architecture(s) | Supported operating system(s) | CPU extension(s) used | No branching-on-secrets claimed? | No branching-on-secrets checked by valgrind? | Large stack usage? | |:---------------------------------:|:-------------------------|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | [Primary Source](#primary-source) | clean | All | All | None | False | False | False | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2 | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## SPHINCS+-SHAKE-128s-simple implementation characteristics | Implementation source | Identifier in upstream | Supported architecture(s) | Supported operating system(s) | CPU extension(s) used | No branching-on-secrets claimed? | No branching-on-secrets checked by valgrind? | Large stack usage? | |:---------------------------------:|:-------------------------|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | [Primary Source](#primary-source) | clean | All | All | None | False | False | False | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2 | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## SPHINCS+-SHAKE-192f-simple implementation characteristics | Implementation source | Identifier in upstream | Supported architecture(s) | Supported operating system(s) | CPU extension(s) used | No branching-on-secrets claimed? | No branching-on-secrets checked by valgrind? | Large stack usage? | |:---------------------------------:|:-------------------------|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | [Primary Source](#primary-source) | clean | All | All | None | False | False | False | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2 | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## SPHINCS+-SHAKE-192s-simple implementation characteristics | Implementation source | Identifier in upstream | Supported architecture(s) | Supported operating system(s) | CPU extension(s) used | No branching-on-secrets claimed? | No branching-on-secrets checked by valgrind? | Large stack usage? | |:---------------------------------:|:-------------------------|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | [Primary Source](#primary-source) | clean | All | All | None | False | False | False | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2 | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## SPHINCS+-SHAKE-256f-simple implementation characteristics | Implementation source | Identifier in upstream | Supported architecture(s) | Supported operating system(s) | CPU extension(s) used | No branching-on-secrets claimed? | No branching-on-secrets checked by valgrind? | Large stack usage? | |:---------------------------------:|:-------------------------|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | [Primary Source](#primary-source) | clean | All | All | None | False | False | False | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2 | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## SPHINCS+-SHAKE-256s-simple implementation characteristics | Implementation source | Identifier in upstream | Supported architecture(s) | Supported operating system(s) | CPU extension(s) used | No branching-on-secrets claimed? | No branching-on-secrets checked by valgrind? | Large stack usage? | |:---------------------------------:|:-------------------------|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | [Primary Source](#primary-source) | clean | All | All | None | False | False | False | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2 | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Explanation of Terms - **Large Stack Usage**: Implementations identified as having such may cause failures when running in threads or in constrained environments.