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/8e221ae797b229858a0b0d784577a8cb149d5789
  • 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)
Classic-McEliece-348864	NA	IND-CCA2	1	261120	6492	96	32
Classic-McEliece-348864f	NA	IND-CCA2	1	261120	6492	96	32
Classic-McEliece-460896	NA	IND-CCA2	3	524160	13608	156	32
Classic-McEliece-460896f	NA	IND-CCA2	3	524160	13608	156	32
Classic-McEliece-6688128	NA	IND-CCA2	5	1044992	13932	208	32
Classic-McEliece-6688128f	NA	IND-CCA2	5	1044992	13932	208	32
Classic-McEliece-6960119	NA	IND-CCA2	5	1047319	13948	194	32
Classic-McEliece-6960119f	NA	IND-CCA2	5	1047319	13948	194	32
Classic-McEliece-8192128	NA	IND-CCA2	5	1357824	14120	208	32
Classic-McEliece-8192128f	NA	IND-CCA2	5	1357824	14120	208	32

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	clean	All	All	None	False	False	True
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 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	clean	All	All	None	False	False	True
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	clean	All	All	None	False	False	True
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	clean	All	All	None	False	False	True
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	clean	All	All	None	False	False	True
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	clean	All	All	None	False	False	True
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	clean	All	All	None	False	False	True
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	clean	All	All	None	False	False	True
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	clean	All	All	None	False	False	True
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	clean	All	All	None	False	False	True
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.