Secure your container images with signature verification

The use of version control systems and other tools in software development has increased efficiency but also expanded the number of entry points for malicious code injections. CI/CD pipelines, with their privileged permissions and access to downstream container registries, are a valuable target for attackers. To increase resiliency across the software supply chain, organizations have implemented systems such as cryptographic provenance for container images through signing and runtime verification. This involves generating unique signatures for each container image during build time using public key signing algorithms, then verifying these signatures downstream to ensure that the image has not been tampered with. Image signature verification can be done at various points in the supply chain, including within the Kubernetes control plane or further downstream within the container runtime. Adopting cryptographic open standards and integrating signatures into existing CI configurations are important considerations before implementing image signing and verification.