Releases after version 5.3.8 attach these files to each GitHub release:

• the wheel and the source distribution (sdist), as published on PyPI;
• the software bill of materials (SBOM), pythainlp-<version>.spdx3.json, byte-identical to the SBOM embedded in the wheel at .dist-info/sboms/ (PEP 770);
• a Sigstore bundle (<file>.sigstore.json) for each of the three files above.

Each of the three files also has a GitHub artifact attestation (build provenance).

To verify a downloaded file, put <file> and <file>.sigstore.json in the same directory, then run:

pip install sigstore
python -m sigstore verify github <file> \
  --cert-identity https://github.com/PyThaiNLP/pythainlp/.github/workflows/pypi-publish.yml@refs/tags/v<version>
gh attestation verify <file> -R PyThaiNLP/pythainlp \
  --signer-workflow PyThaiNLP/pythainlp/.github/workflows/pypi-publish.yml \
  --source-ref refs/tags/v<version>

<file> is the wheel, the sdist, or the SBOM.

The following security improvements are planned for future releases:

• Migrate from pickle to a safer serialization format such as JSON or MessagePack.
• Upgrade the hashing algorithm for integrity verification from MD5 to SHA-256 or SHA-3.
• Implement digital signatures for corpus files to ensure authenticity.
• Add version tracking to the corpus to prevent rollback attacks.