# Classic McEliece - **Algorithm type**: Key encapsulation mechanism. - **Main cryptographic assumption**: Niederreiter's dual version of McEliece's public key encryption using binary Goppa codes. - **Principal submitters**: Daniel J. Bernstein, Tung Chou, Tanja Lange, Ingo von Maurich, Rafael Misoczki, Ruben Niederhagen, Edoardo Persichetti, Christiane Peters, Peter Schwabe, Nicolas Sendrier, Jakub Szefer, Wen Wang. - **Authors' website**: https://classic.mceliece.org - **Specification version**: SUPERCOP-20221025. - **Primary Source**: - **Source**: https://github.com/PQClean/PQClean/commit/1eacfdafc15ddc5d5759d0b85b4cef26627df181 with copy_from_upstream patches - **Implementation license (SPDX-Identifier)**: Public domain - **Ancestors of primary source**: - SUPERCOP-20221025 "clean" and "avx2" implementations ## Advisories - Classic-McEliece-460896, Classic-McEliece-460896f, Classic-McEliece-6960119, and Classic-McEliece-6960119f parameter sets fail memory leak testing on x86-64 when building with ``clang`` using optimization level ``-O2`` and ``-O3``. Care is advised when using the algorithm at higher optimization levels, and any other compiler and architecture. - Current implementation of the algorithm may not be constant-time. Additionally, environment specific constant-time leaks may not be documented; please report potential constant-time leaks when found. ## Parameter set summary | Parameter set | Parameter set alias | Security model | Claimed NIST Level | Public key size (bytes) | Secret key size (bytes) | Ciphertext size (bytes) | Shared secret size (bytes) | Keypair seed size (bytes) | Encapsulation seed size (bytes) | |:-------------------------:|:----------------------|:-----------------|---------------------:|--------------------------:|--------------------------:|--------------------------:|-----------------------------:|:----------------------------|:----------------------------------| | Classic-McEliece-348864 | NA | IND-CCA2 | 1 | 261120 | 6492 | 96 | 32 | NA | NA | | Classic-McEliece-348864f | NA | IND-CCA2 | 1 | 261120 | 6492 | 96 | 32 | NA | NA | | Classic-McEliece-460896 | NA | IND-CCA2 | 3 | 524160 | 13608 | 156 | 32 | NA | NA | | Classic-McEliece-460896f | NA | IND-CCA2 | 3 | 524160 | 13608 | 156 | 32 | NA | NA | | Classic-McEliece-6688128 | NA | IND-CCA2 | 5 | 1044992 | 13932 | 208 | 32 | NA | NA | | Classic-McEliece-6688128f | NA | IND-CCA2 | 5 | 1044992 | 13932 | 208 | 32 | NA | NA | | Classic-McEliece-6960119 | NA | IND-CCA2 | 5 | 1047319 | 13948 | 194 | 32 | NA | NA | | Classic-McEliece-6960119f | NA | IND-CCA2 | 5 | 1047319 | 13948 | 194 | 32 | NA | NA | | Classic-McEliece-8192128 | NA | IND-CCA2 | 5 | 1357824 | 14120 | 208 | 32 | NA | NA | | Classic-McEliece-8192128f | NA | IND-CCA2 | 5 | 1357824 | 14120 | 208 | 32 | NA | NA | ## Classic-McEliece-348864 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 | True | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2,POPCNT | False | False | True | 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. ## Classic-McEliece-348864f 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 | True | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2,POPCNT,BMI1 | False | False | True | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Classic-McEliece-460896 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 | True | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2,POPCNT | False | False | True | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Classic-McEliece-460896f 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 | True | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2,POPCNT,BMI1 | False | False | True | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Classic-McEliece-6688128 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 | True | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2,POPCNT | False | False | True | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Classic-McEliece-6688128f 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 | True | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2,POPCNT,BMI1 | False | False | True | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Classic-McEliece-6960119 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 | True | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2,POPCNT | False | False | True | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Classic-McEliece-6960119f 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 | True | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2,POPCNT,BMI1 | False | False | True | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Classic-McEliece-8192128 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 | True | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2,POPCNT | False | False | True | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Classic-McEliece-8192128f 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 | True | | [Primary Source](#primary-source) | avx2 | x86\_64 | Linux,Darwin | AVX2,POPCNT,BMI1 | False | False | True | 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.