diff --git a/.github/workflows/release-check.yml b/.github/workflows/release-check.yml
new file mode 100644
index 0000000..0f7d1ec
--- /dev/null
+++ b/.github/workflows/release-check.yml
@@ -0,0 +1,51 @@
+name: Supply Chain Check
+
+on:
+  pull_request:
+    paths:
+      - ".github/workflows/release.yml"
+      - ".github/workflows/release-check.yml"
+      - "composer.json"
+
+permissions:
+  contents: read
+
+jobs:
+  verify-release-artifacts:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "8.4"
+          extensions: simplexml, zip
+          coverage: none
+
+      - name: Install runtime dependencies
+        run: composer install --no-dev --prefer-dist --no-progress --no-interaction
+
+      - name: Create test package
+        run: composer archive --format=zip --file=elp-parser-test
+
+      - name: Generate test CycloneDX SBOM
+        uses: anchore/sbom-action@v0.24.2
+        with:
+          path: .
+          format: cyclonedx-json
+          output-file: elp-parser-test.cdx.json
+          upload-artifact: false
+          upload-release-assets: false
+
+      - name: Generate and verify checksums
+        run: |
+          sha256sum elp-parser-test.zip elp-parser-test.cdx.json > SHA256SUMS
+          sha256sum --check SHA256SUMS
+
+      - name: Validate CycloneDX document
+        run: |
+          jq -e '.bomFormat == "CycloneDX"' elp-parser-test.cdx.json
+          jq -e '.specVersion != null' elp-parser-test.cdx.json
+          jq -e '.metadata.component != null' elp-parser-test.cdx.json
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 2869696..354de33 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -10,31 +10,68 @@ jobs:
   build:
     runs-on: ubuntu-latest
     permissions:
+      actions: read
+      attestations: write
       contents: write
+      id-token: write
+
     steps:
       - uses: actions/checkout@v7
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: '8.0'
+          php-version: "8.4"
           extensions: simplexml, zip
           coverage: none
 
-      - name: Install dependencies
-        run: composer install --no-dev --prefer-dist --no-progress
+      - name: Install runtime dependencies
+        run: composer install --no-dev --prefer-dist --no-progress --no-interaction
 
       - name: Get tag
         id: tag
-        run: echo "tag=${GITHUB_REF#refs/tags/}" >> $GITHUB_OUTPUT
+        run: echo "tag=${GITHUB_REF#refs/tags/}" >> "$GITHUB_OUTPUT"
 
       - name: Create package
-        run: composer archive --format=zip --file="elp-parser-${{ steps.tag.outputs.tag }}"
+        run: |
+          composer archive \
+            --format=zip \
+            --file="elp-parser-${{ steps.tag.outputs.tag }}"
+
+      - name: Generate CycloneDX SBOM
+        uses: anchore/sbom-action@v0.24.2
+        with:
+          path: .
+          format: cyclonedx-json
+          output-file: elp-parser-${{ steps.tag.outputs.tag }}.cdx.json
+          upload-artifact: false
+          upload-release-assets: false
+
+      - name: Generate checksums
+        run: |
+          sha256sum \
+            "elp-parser-${{ steps.tag.outputs.tag }}.zip" \
+            "elp-parser-${{ steps.tag.outputs.tag }}.cdx.json" \
+            > SHA256SUMS
+
+      - name: Attest build provenance
+        uses: actions/attest-build-provenance@v4.2.2
+        with:
+          subject-path: elp-parser-${{ steps.tag.outputs.tag }}.zip
+
+      - name: Attest SBOM
+        uses: actions/attest-sbom@v4.1.0
+        with:
+          subject-path: elp-parser-${{ steps.tag.outputs.tag }}.zip
+          sbom-path: elp-parser-${{ steps.tag.outputs.tag }}.cdx.json
 
       - name: Create Release
         uses: softprops/action-gh-release@v3
         with:
-          files: elp-parser-${{ steps.tag.outputs.tag }}.zip
+          files: |
+            elp-parser-${{ steps.tag.outputs.tag }}.zip
+            elp-parser-${{ steps.tag.outputs.tag }}.cdx.json
+            SHA256SUMS
           draft: false
           prerelease: false
           generate_release_notes: true
diff --git a/README.md b/README.md
index 43aa0d5..b9493fd 100644
--- a/README.md
+++ b/README.md
@@ -429,6 +429,10 @@ php tests/upstream-compat.php /path/to/exelearning/test/fixtures
 - [Security policy](SECURITY.md)
 - [Changelog](CHANGELOG.md)
 
+## Release integrity
+
+Tagged releases publish a CycloneDX SBOM, SHA-256 checksums and GitHub artifact attestations for build provenance and the SBOM. See [Release supply chain](docs/supply-chain.md).
+
 ## License
 
 The project is distributed under the MIT License. See [LICENSE.md](LICENSE.md).
diff --git a/docs/supply-chain.md b/docs/supply-chain.md
new file mode 100644
index 0000000..90053e4
--- /dev/null
+++ b/docs/supply-chain.md
@@ -0,0 +1,28 @@
+# Release supply chain
+
+Tagged releases publish more than the Composer archive.
+
+Each release contains:
+
+- `elp-parser-<tag>.zip` — distributable package archive;
+- `elp-parser-<tag>.cdx.json` — CycloneDX JSON software bill of materials;
+- `SHA256SUMS` — SHA-256 checksums for the archive and SBOM.
+
+GitHub Artifact Attestations are also created for:
+
+- build provenance of the ZIP artifact;
+- the CycloneDX SBOM bound to that ZIP artifact.
+
+The attestation actions use GitHub OIDC and repository-scoped workflow permissions; no additional signing key or long-lived secret is stored in the repository.
+
+## Verify checksums
+
+```bash
+sha256sum --check SHA256SUMS
+```
+
+## Verify GitHub attestations
+
+Consumers with the GitHub CLI can verify release artifact attestations using GitHub's artifact-attestation commands against the repository identity.
+
+A dedicated pull-request workflow builds a test archive, generates the SBOM and validates checksums/CycloneDX structure so release packaging changes are checked before a tag is created.
diff --git a/mkdocs.yml b/mkdocs.yml
index e908822..78b2c1f 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -59,6 +59,7 @@ nav:
   - Guides:
       - Validation: validation.md
       - Security: security.md
+      - Release Supply Chain: supply-chain.md
       - iDevices: idevices.md
       - Assets and Package Entries: assets.md
       - Performance: performance.md