Typical keyless use: cosign sign registry/image@sha256:… in CI, then cosign verify --certificate-identity https://github.com/org/repo/.github/workflows/release.yml@refs/tags/v1.2.3 --certificate-oidc-issuer https://token.actions.githubusercontent.com registry/image@sha256:…. Signatures and attestations are stored in the registry next to the image (as OCI artifacts, increasingly as Sigstore bundles with the referrers API).
Always sign and verify by digest, not by tag, and always pin both identity and issuer (or use the regular-expression variants deliberately). Admission controllers such as the Sigstore policy-controller and Kyverno enforce cosign verification in Kubernetes.