标签：#supplychainsecurity

Container Image Signing & SLSA Provenance Verification with Sigstore Cosign Supply chain security guide on signing OCI container images keylessly and verifying SLSA build provenance using Sigstore Cosign and Rekor. Executive Summary & Key Takeaways Keyless Image Signing: Sign OCI container images in CI/CD using OIDC identity tokens (Fulcio CA) without managing private keys. Immutable Transparency Log: Record signature metadata in the public Rekor transparency log to prevent signature tampering. SLSA Provenance Attestation: Attach cryptographically signed SLSA build provenance attestations to container images. Kyverno Policy Enforcement: Block un-signed or non-compliant container images from running in Kubernetes clusters. 1. Software Supply Chain Risks & Container Image Signing Container registries (Docker Hub, GHCR) store execution binaries for enterprise applications. If an attacker compromises CI/CD credentials or registry access, they can replace legitimate container tags with malicious images containing backdoors. Sigstore Cosign eliminates supply chain tampering by cryptographically signing OCI container images during the CI/CD build process. Using keyless signing powered by Fulcio (certificate authority) and Rekor (transparency log), Cosign binds OIDC identities (e.g., GitHub Actions workflow identity) to container digests without long-lived private keys. This ensures that container images running in Kubernetes can be traced back to exact GitHub workflow runs. Keyless signing eliminates the security liability of storing long-lived signing keys in CI/CD secrets. Cryptographic digest binding guarantees that tag overwrite attacks are detected immediately by container runtimes. Implementing automated continuous monitoring across production nodes ensures that compliance policies remain enforced during infrastructure updates. Regular security audits should be integrated into DevOps CI/CD pipelines to verify that system configurations conform to zero-trust architect