diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index f12f9bf5..875357a7 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -41,12 +41,24 @@ jobs:
     runs-on: ubuntu-latest
     permissions:
       contents: write
+      id-token: write # keyless Sigstore signing (OIDC); no signing key exists
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
         with:
           name: dist
           path: dist/
+      - name: Sign artifacts with Sigstore (keyless, OIDC)
+        # Produces dist/<artifact>.sigstore.json bundles next to each wheel/sdist.
+        # The 'gh release create dist/*' step below then attaches them to the
+        # GitHub Release, which is where Scorecard's Signed-Releases check looks.
+        # release-signing-artifacts is disabled: the action's own auto-attach only
+        # fires on a 'release: published' event, but we trigger on 'push: tags',
+        # so we upload the bundles ourselves via the dist/* glob.
+        uses: sigstore/gh-action-sigstore-python@04cffa1d795717b140764e8b640de88853c92acc # v3.3.0
+        with:
+          inputs: ./dist/*.tar.gz ./dist/*.whl
+          release-signing-artifacts: false
       - name: Extract latest CHANGELOG section
         run: |
           # Grab the topmost "## [...]" block from CHANGELOG.md as release notes.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d2c2e72a..f83c1f6a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,13 @@ and this project uses [Calendar Versioning](https://calver.org/) in the format
   default broad `GITHUB_TOKEN` scopes — dropping the OpenSSF Scorecard
   Token-Permissions check to 0. Added `permissions: contents: read`; the
   workflow only reads the repo to build and smoke-test the wheel.
+- **Signed GitHub Releases via Sigstore (keyless).** The release workflow now
+  signs the built wheel + sdist with `sigstore/gh-action-sigstore-python`
+  (keyless OIDC — no signing key is generated, stored, or held by anyone) and
+  attaches the resulting `.sigstore.json` bundles to the GitHub Release. PyPI
+  uploads were already attested via Trusted Publishing; this extends verifiable
+  provenance to artifacts pulled from GitHub Releases and satisfies the OpenSSF
+  Scorecard Signed-Releases check. First proof lands on the next `v*` tag.
 
 ---