Python Cryptography Breaks Up with OpenSSL with Paul Kehrer and Alex Gaynor

The Python cryptography module, pyca/cryptography, has mostly been a sane wrapper around a pile of C, so that users get performant cryptography on the many, many platforms Python targets. Therefore its maintainers, Alex Gaynor and Paul Kehrer, have become intimately familiar with OpenSSL. Recently, they declared that after many years of trying to make it work, they announced pyca/cryptography would be moving away from OpenSSL when supporting new functionality and exploring adding other backends instead. We invited them on to tell us about what has happened to OpenSSL, even after the investments and improvements following Heartbleed. No guests on this pod represent anyone besides themselves.

Watch on YouTube: https://www.youtube.com/watch?v=dEKBHI3rodY

Transcript: https://securitycryptographywhatever.com/2026/02/01/python-cryptography-breaks-up-with-openssl

Links:
- https://cryptography.io/en/latest/statements/state-of-openssl/
- Py Cryptography: https://cryptography.io
- https://archive.openssl-conference.org/2025/presentations/Alex_Gaynor_Paul_Kehrer_The_Python_Cryptographic_Authoritys_OpenSSL_Experience.pdf
- https://securitycryptographywhatever.com/2025/08/16/alex-gaynor/
- https://packages.gentoo.org/packages/media-libs/libsdl
- https://www.youtube.com/watch?v=RUIguklWwx0
- https://datatracker.ietf.org/doc/rfc9180/
- https://docs.openssl.org/3.3/man3/OSSL_PARAM/
- https://openssl.foundation/
- https://github.com/openssl/openssl/issues/17064
- https://www.feistyduck.com/newsletter/issue_132_openssl_performance_still_under_scrutiny
- https://github.com/topazproject/topaz
- https://github.com/actions/runner/issues/1069
- https://crystalhotsauce.com/
- https://openssl-library.org/news/vulnerabilities/#CVE-2025-15467
- https://en.wikipedia.org/wiki/Ship_of_Theseus
- https://boringssl.googlesource.com/boringssl/+/aa202db1d7091b88b80f0a58c630c5c1aefc817d
- https://www.ibm.com/products/open-sdk-for-rust-aix
- https://dadrian.io/blog/posts/corporate-support-xz/
- https://peps.python.org/
- https://cryptography.io/en/latest/hazmat/primitives/asymmetric/ed448/
- https://go.dev/blog/fips140
- https://dadrian.io/blog/posts/roll-your-own-crypto/

"Security Cryptography Whatever" is hosted by Deirdre Connolly (@durumcrustulum), Thomas Ptacek (@tqbf), and David Adrian (@dadrian)