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SLSA

SLSA — the supply chain integrity framework. Four levels of build provenance assurance from basic to hermetic. Google-originated, OpenSSF-maintained. The standard for "where did this artifact come from?"

Key takeaways

  • Supply chain integrity framework with four levels of build provenance assurance — from basic (unsigned provenance) to hermetic (isolated, reproducible builds with signed provenance)
  • Answers "where did this artifact come from?" with cryptographically verifiable build provenance attestations
  • Google-originated, OpenSSF-maintained. GitHub Actions generators produce SLSA provenance automatically. Used by Go, npm, and major package registries
  • Complements Sigstore (signing) and Scorecard (scoring) — together they form the trust infrastructure stack

FAQ

What is SLSA?

A supply chain integrity framework (pronounced "salsa") that defines four levels of build provenance assurance. Provides cryptographically verifiable attestations proving where software artifacts came from and how they were built. Google-originated, OpenSSF-maintained.

Overview

SLSA (Supply-chain Levels for Software Artifacts, pronounced "salsa") is a supply chain integrity framework that defines four levels of build provenance assurance. It answers the fundamental trust question: "Where did this artifact come from, and can I verify it?"

Four levels from L1 (basic provenance documentation) to L4 (hermetic, reproducible builds with signed, non-falsifiable provenance). GitHub Actions generators produce SLSA provenance automatically.

Complements Sigstore (signing) and OpenSSF Scorecard (scoring) in the trust infrastructure stack.


Competitive Position

Strengths: Industry standard framework. Google + OpenSSF backing. GitHub Actions integration. Complementary to Sigstore/Scorecard.

Weaknesses: Framework, not a tool — requires tooling to implement. Higher levels (L3-L4) are difficult to achieve. Adoption outside large orgs is slow.


Research by Ry Walker Research