Methodologies
SLSA Level 3: Hardening the Software Supply Chain
SLSA v1.0, published in April 2023, defines four maturity levels for securing the software supply chain, from basic provenance to isolated builds. Level 3 requires every build to run in an ephemeral, stateless environment, eliminating attacks like build contamination and insider threat, and is achievable with GitHub Actions and OIDC signing via Sigstore.