Binary Authorization

Binary Authorization relies on a digital signature verification chain to establish trust. A container image is signed by a trusted authority using a private key, and the admission controller verifies this signature against a configured public key before allowing deployment. This creates a tamper-evident artifact identity.

• Uses Cosign or Notation for signing OCI artifacts
• Validates signatures against a trusted keyring or certificate authority
• Prevents deployment of unsigned or modified images
• Integrates with Sigstore for keyless signing via OIDC identities

A Binary Authorization policy defines the rules that govern which images are permitted. Policies are evaluated by an admission controller webhook at deploy time, blocking any workload that violates constraints. This decouples policy logic from the deployment pipeline.

• Policies written as YAML or JSON rule sets
• Supports allowlist patterns for specific registries, repositories, or image digests
• Can require multiple attestations from different authorities
• Enforces break-glass exceptions with time-bound overrides

Binary Authorization extends trust beyond the image itself to the entire software supply chain. Attestations can verify that an image passed specific build steps, vulnerability scans, or compliance checks before it is eligible for deployment.

• Validates SLSA provenance attestations
• Requires Vulnerability Scanning results as a deploy condition
• Chains in-toto attestations for end-to-end build verification
• Prevents supply chain attacks by rejecting images from compromised pipelines

Trust is not a one-time event. Binary Authorization systems continuously monitor running workloads to detect configuration drift where a deployed image no longer matches the currently approved policy or its signature has been revoked.

• Monitors for signature expiration and revocation
• Detects unauthorized image mutations in running clusters
• Integrates with admission controllers for real-time re-validation
• Alerts on policy violations in production environments

Binary Authorization bridges the gap between build-time security and deploy-time enforcement. Signing occurs as the final step in a trusted CI/CD pipeline, cryptographically linking the built artifact to the process that created it.

• Automated signing in GitHub Actions, GitLab CI, or Jenkins
• Keyless signing using workload identity federation
• Stores signatures in OCI registries alongside images
• Enables gated promotions between environments based on attestation presence

Operational realities require controlled flexibility. Binary Authorization supports break-glass mechanisms that allow authorized personnel to bypass policy enforcement for emergency fixes, with all exceptions logged immutably for audit.

• Time-bound exemptions that auto-expire
• Just-in-time approval workflows for emergency deployments
• Immutable audit trails for every policy override
• Integration with incident management systems for context-aware exceptions

A secure area of a main processor that guarantees the confidentiality and integrity of code and data loaded inside it. In the context of Binary Authorization, a TEE can be used to host the policy enforcement point itself, ensuring that the verification logic cannot be tampered with by a compromised host operating system or hypervisor.

• Hardware: Intel SGX, AMD SEV, and ARM TrustZone.
• Benefit: Protects the signing keys and policy engine from insider threats at the infrastructure layer.

A set of unconditionally trusted hardware or software components that form the foundational security building blocks. For Binary Authorization, the Root of Trust is the cryptographic key pair used to sign container digests. If this root key is compromised, the entire verification chain collapses, allowing unauthorized images to be deployed.

• Hardware Root: A Hardware Security Module (HSM) or KMS service that prevents private key extraction.
• Chain of Trust: The root CA signs intermediate keys, which sign image digests.

A security standard that ensures a device boots using only software that is cryptographically verified by the Original Equipment Manufacturer. Binary Authorization extends the concept of Secure Boot from the physical machine level to the container orchestration layer, ensuring that only verified code executes in production, preventing the deployment of backdoored or tampered images.

• Analogy: Secure Boot verifies the kernel; Binary Authorization verifies the user-space containers.
• Result: A complete chain of trust from firmware to application code.