--- title: One Signed Answer: SLSA Verification Summaries for... description: Kubernetes' image promoter attaches a signed SLSA verification summary (VSA) to every image it promotes to registry.k8s.io, starting October 2026. The summary... canonical: https://daily.dev/posts/one-signed-answer-slsa-verification-summaries-for-registry-k8s-io-images-lttkxuayf twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: One Signed Answer: SLSA Verification Summaries for registry.k8s.io Images | daily.dev og:description: Kubernetes' image promoter attaches a signed SLSA verification summary (VSA) to every image it promotes to registry.k8s.io, starting October 2026. The summary... og:url: https://daily.dev/posts/one-signed-answer-slsa-verification-summaries-for-registry-k8s-io-images-lttkxuayf og:image: https://api.daily.dev/og/posts/LttkxuaYF.png og:image:alt: One Signed Answer: SLSA Verification Summaries for registry.k8s.io Images og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # One Signed Answer: SLSA Verification Summaries for registry.k8s.io Images **[K8S Contributors](https://daily.dev/sources/k8s_contrib)** · 13 min read · 0 upvotes · 0 comments ## Summary Kubernetes' image promoter attaches a signed SLSA verification summary (VSA) to every image it promotes to registry.k8s.io, starting October 2026. The summary states whether the image's build provenance passed a project's declared policy, and at which SLSA build level, so developers can check it without manually verifying signer identity, builder, and source repo themselves. The Security Profiles Operator is the first project using it, with its v1.1.1 operator images, spoc binaries, and Helm chart verified at SLSA build level 3. Verification uses cosign and the SLSA verifier v0.1.0, and the summary is kept once issued, while most images promoted before October 2026 have none. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How do I verify the SLSA build level of a Kubernetes image on registry.k8s.io? Use cosign v3 to verify the attestation signed by promoter-summaries@k8s-releng-prod.iam.gserviceaccount.com, then pipe it through jq to check the verifier ID equals 'https://k8s.io/promo-tools/verifier/v1', the verificationResult is 'PASSED', and verifiedLevels includes the required SLSA level. Alternatively, run the SLSA verifier v0.1.0 (slsa-framework/verifier) with the --verifier, --level, and --subject flags against the downloaded VSA. _Teams hardening their container supply chain can track SLSA tooling changes like this on daily.dev._ ### What is the difference between SLSA build level 1 and level 3 for container images? Level 1 only requires that provenance exists showing how the artifact was built, protecting against mistakes but allowing the build itself to write and sign its own provenance, which could be tampered with. Level 3 requires a hardened build platform whose build steps cannot influence the provenance or reach its signing key, protecting against tampering during the build itself. Cloud Build typically reaches level 1, while an isolated GitHub Actions workflow can reach level 3. _Developers deciding how much build isolation to invest in can follow SLSA level discussions on daily.dev._ ### Why does my Kubernetes-promoted container image have no SLSA verification summary? Verification summaries for registry.k8s.io images only started being generated since October 2026, and a digest receives its summary once, at promotion time, permanently. Most images promoted before that date have no summary at all, and adding a provenance policy later does not retroactively apply to already-promoted digests, so a project must add its policy before promoting the images it wants summarized. _Anyone rolling out supply-chain verification requirements can check tooling updates like this on daily.dev._ ## Similar posts on daily.dev - [Software Supply Chain Security: Why 99% of Your Container is Mystery Code](https://daily.dev/posts/software-supply-chain-security-why-99-of-your-container-is-mystery-code-0o8ohjmsz) · Cloud Native Now · 0 upvotes · 0 comments - [Making the Most of Your Docker Hardened Images Enterprise Trial – Part 2](https://daily.dev/posts/making-the-most-of-your-docker-hardened-images-enterprise-trial-part-2-67ueaj5ym) · Docker · 0 upvotes · 0 comments - [Security Profiles Operator v1: Stable APIs, Security Hardened, and Shaping Upstream Kubernetes](https://daily.dev/posts/security-profiles-operator-v1-stable-apis-security-hardened-and-shaping-upstream-kubernetes-nhsj8onsp) · CNCF · 9 upvotes · 0 comments - [HashiCorp Packer 1.16 Adds Native SLSA Provenance Generation and Verification for Machine Images](https://daily.dev/posts/hashicorp-packer-1-16-adds-native-slsa-provenance-generation-and-verification-for-machine-images-oc3i7ffyp) · InfoQ · 2 upvotes · 0 comments - [Signing and verifying container images with Cosign and Sigstore](https://daily.dev/posts/signing-and-verifying-container-images-with-cosign-and-sigstore-py88l4cfh) · Security Boulevard · 0 upvotes · 0 comments --- Tags: [#security](https://daily.dev/tags/security), [#kubernetes](https://daily.dev/tags/kubernetes), [#containers](https://daily.dev/tags/containers) [View this post on daily.dev](https://daily.dev/posts/one-signed-answer-slsa-verification-summaries-for-registry-k8s-io-images-lttkxuayf) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"One Signed Answer: SLSA Verification Summaries for registry.k8s.io Images","url":"https://daily.dev/posts/one-signed-answer-slsa-verification-summaries-for-registry-k8s-io-images-lttkxuayf","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/one-signed-answer-slsa-verification-summaries-for-registry-k8s-io-images-lttkxuayf"},"datePublished":"2026-10-28T00:09:28.678Z","dateModified":"2026-10-28T03:57:09.352Z","description":"Kubernetes' image promoter attaches a signed SLSA verification summary (VSA) to every image it promotes to registry.k8s.io, starting October 2026. 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