The PyPI blog announced the new security feature of index-hosted digital attestations, replacing the traditional PGP signatures on PyPI. These attestations offer key usability, index verifiability, cryptographic strength, and provenance properties to enhance software supply chain security. Trusted Publishing with attestation support is now enabled by default, requiring minimal changes for existing users. Sigstore integration simplifies key and identity management challenges. Further, PEP 740 combines Sigstore and Trusted Publishing to provide verifiable provenance for packages on PyPI. The long-term goal is to integrate verification processes into individual client installation flows to ensure the authenticity of attestations.
https://blog.trailofbits.com/2024/11/14/attestations-a-new-generation-of-signatures-on-pypi/