# Kyber - **Algorithm type**: Key encapsulation mechanism. - **Main cryptographic assumption**: Module LWE+R with base ring Z[x]/(3329, x^256+1). - **Principal submitters**: Peter Schwabe. - **Auxiliary submitters**: Roberto Avanzi, Joppe Bos, Léo Ducas, Eike Kiltz, Tancrède Lepoint, Vadim Lyubashevsky, John M. Schanck, Gregor Seiler, Damien Stehlé. - **Authors' website**: https://pq-crystals.org/ - **Specification version**: NIST Round 3 submission. - **Implementation source**: https://github.com/pq-crystals/kyber/commit/8e9308bd with copy_from_upstream patches - **Implementation license (SPDX-Identifier)**: CC0-1.0. ## Parameter set summary | Parameter set | Security model | Claimed NIST Level | Public key size (bytes) | Secret key size (bytes) | Ciphertext size (bytes) | Shared secret size (bytes) | |:---------------:|:-----------------|---------------------:|--------------------------:|--------------------------:|--------------------------:|-----------------------------:| | Kyber512 | IND-CCA2 | 1 | 800 | 1632 | 768 | 32 | | Kyber512-90s | IND-CCA2 | 1 | 800 | 1632 | 768 | 32 | | Kyber768 | IND-CCA2 | 3 | 1184 | 2400 | 1088 | 32 | | Kyber768-90s | IND-CCA2 | 3 | 1184 | 2400 | 1088 | 32 | | Kyber1024 | IND-CCA2 | 5 | 1568 | 3168 | 1568 | 32 | | Kyber1024-90s | IND-CCA2 | 5 | 1568 | 3168 | 1568 | 32 | ## Kyber512 implementation characteristics | 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? | |:------------------------:|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | ref | All | All | None | True | True | False | | avx2 | x86\_64 | Linux,Darwin | AVX2,BMI2,POPCNT | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Kyber512-90s implementation characteristics | 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? | |:------------------------:|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | ref | All | All | None | True | True | False | | avx2 | x86\_64 | Linux,Darwin | AES,AVX2,BMI2,POPCNT | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Kyber768 implementation characteristics | 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? | |:------------------------:|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | ref | All | All | None | True | True | False | | avx2 | x86\_64 | Linux,Darwin | AVX2,BMI2,POPCNT | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Kyber768-90s implementation characteristics | 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? | |:------------------------:|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | ref | All | All | None | True | True | False | | avx2 | x86\_64 | Linux,Darwin | AES,AVX2,BMI2,POPCNT | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Kyber1024 implementation characteristics | 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? | |:------------------------:|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | ref | All | All | None | True | True | False | | avx2 | x86\_64 | Linux,Darwin | AVX2,BMI2,POPCNT | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**. ## Kyber1024-90s implementation characteristics | 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? | |:------------------------:|:----------------------------|:--------------------------------|:------------------------|:-----------------------------------|:-----------------------------------------------|:---------------------| | ref | All | All | None | True | True | False | | avx2 | x86\_64 | Linux,Darwin | AES,AVX2,BMI2,POPCNT | True | True | False | Are implementations chosen based on runtime CPU feature detection? **Yes**.