Anthropic-Cybersecurity-Skills/skills/implementing-supply-chain-security-with-in-toto/references/standards.md

Standards and References - Supply Chain Security with in-toto

Industry Standards

SLSA (Supply chain Levels for Software Artifacts)

• in-toto provides the attestation framework that SLSA builds upon
• SLSA provenance attestations use in-toto attestation format
• Graduated to v1.0 specification with clear level requirements

NIST SSDF (Secure Software Development Framework) SP 800-218

• PO.1.1: Define and document security requirements for software
• PS.1.1: Verify third-party software components
• PW.4.1: Review and analyze source code for security vulnerabilities

NIST SP 800-204D: Strategies for Securing the Software Supply Chain

• Section 4: Build system integrity verification
• Section 5: Attestation-based supply chain verification
• Recommends cryptographic provenance tracking

Executive Order 14028 (Improving the Nation's Cybersecurity)

• Requires SBOM generation for software sold to federal government
• Mandates supply chain security for critical software
• in-toto attestations satisfy provenance requirements

Compliance Mapping

Requirement	Framework	in-toto Capability
Build provenance	SLSA L2+	Signed link metadata per build step
Artifact integrity	NIST 800-204D	SHA-256 hash chaining between steps
Authorized builders	SLSA L3+	Functionary key verification
SBOM generation	EO 14028	Inspection step for SBOM validation
Code review	SLSA L4	Threshold signing with multiple reviewers
Tamper detection	PCI DSS 6.5	End-to-end verification before deployment

Ecosystem Integration

Sigstore

• Keyless signing via Fulcio certificate authority
• Transparency log via Rekor for attestation persistence
• Cosign for container image signing and verification

Witness / Archivista

• Witness: in-toto implementation focused on cloud-native CI/CD
• Archivista: Attestation storage and retrieval service
• Both used by SolarWinds for supply chain integrity post-breach

OpenVEX

• Vulnerability Exploitability eXchange format
• Complements in-toto attestations with vulnerability status
• Allows marking CVEs as "not affected" for specific builds