SLSA Framework

The foundational level requires automated generation of provenance—a verifiable statement about how an artifact was built. This includes the build entry point, source materials, and build parameters. The provenance must be available for inspection but does not yet require cryptographic signing or tamper-proof storage. This level enables basic vulnerability management and inventory analysis.

This level requires provenance to be cryptographically signed by a trusted build service. Key requirements include:

• The build service must generate and sign the provenance
• Consumers can verify the signature against a known identity
• The signing key must be managed by the build service, not the user This prevents attackers from forging provenance metadata after a compromise.

The highest level mandates a tamper-proof build environment with strong isolation and auditability. Requirements include:

• Hermetic builds: No network access or undefined inputs during the build
• Isolation: Build steps run in isolated containers or VMs
• Reproducibility: Independent rebuilds produce bit-for-bit identical artifacts
• Audit trails: All build steps are logged in a verifiable transparency ledger This level defends against sophisticated insider threats and compromised build infrastructure.