diff --git a/.gitea/workflows/release.yaml b/.gitea/workflows/release.yaml
index b3b9c08..0eb00b6 100644
--- a/.gitea/workflows/release.yaml
+++ b/.gitea/workflows/release.yaml
@@ -1,5 +1,10 @@
 name: Release
 
+env:
+  GPG_PRIVATE_KEY_FILE: ${{ runner.temp }}/private.key
+  GPG_PRIVATE_KEY_FINGERPRINT: ${{ vars.GPG_PRIVATE_KEY_FINGERPRINT }}
+  GPG_PRIVATE_KEY_PASSPHRASE_FILE: ${{ runner.temp }}/passphrase.txt
+
 on:
   push:
     tags:
@@ -7,14 +12,58 @@ on:
 
 jobs:
   publish-chart:
-    container:
-      image: docker.io/volkerraschek/helm:3.19.2
     runs-on: ubuntu-latest
     steps:
-      - name: Install packages via apk
+      - uses: volker-raschek/cosign-installer@v4.1.2-rc4
+        with:
+          cosign-release: "v3.0.6" # renovate: datasource=github-tags depName=sigstore/cosign
+
+      - uses: azure/setup-helm@v5.0.0
+        with:
+          version: "v4.1.4" # renovate: datasource=github-tags depName=helm/helm
+
+      - name: Install helm plugins
+        env:
+          HELM_SIGSTORE_VERSION: "0.3.0" # renovate: datasource=github-tags depName=sigstore/helm-sigstore extractVersion='^v(?<version>\d+\.\d+\.\d+)$'
+          HELM_SCHEMA_VALUES_VERSION: "2.4.0" # renovate: datasource=github-tags depName=losisin/helm-values-schema-json extractVersion='^v(?<version>\d+\.\d+\.\d+)$'
+          HELM_UNITTEST_VERSION: "1.0.3" # renovate: datasource=github-tags depName=helm-unittest/helm-unittest extractVersion='^v(?<version>\d+\.\d+\.\d+)$'
         run: |
-          apk update
-          apk add git npm jq yq
+          helm plugin install --verify=false https://github.com/sigstore/helm-sigstore.git --version "${HELM_SIGSTORE_VERSION}" 1> /dev/null
+          helm plugin install --verify=false https://github.com/losisin/helm-values-schema-json.git --version "${HELM_SCHEMA_VALUES_VERSION}" 1> /dev/null
+          helm plugin install --verify=false https://github.com/helm-unittest/helm-unittest.git --version "${HELM_UNITTEST_VERSION}" 1> /dev/null
+          helm plugin list
+
+      - name: GPG configuration
+        env:
+          GPG_PRIVATE_KEY_PASSPHRASE: ${{ secrets.GPG_PRIVATE_KEY_PASSPHRASE }}
+          GPG_PRIVATE_KEY: ${{ secrets.GPG_PRIVATE_KEY }}
+        run: |
+          # Configure GPG and GPG Agent
+          mkdir --parents "${HOME}/.gnupg"
+          chmod 0700 "${HOME}/.gnupg"
+
+          cat > "${HOME}/.gnupg/gpg.conf" <<EOF
+          use-agent
+          pinentry-mode loopback
+          EOF
+
+          cat > "${HOME}/.gnupg/gpg-agent.conf" <<EOF
+          allow-loopback-pinentry
+          max-cache-ttl 86400
+          default-cache-ttl 86400
+          EOF
+
+          gpgconf --kill gpg-agent
+          gpgconf --launch gpg-agent
+
+          # Import GPG private key
+          cat 1> "${GPG_PRIVATE_KEY_PASSPHRASE_FILE}" <<< "${GPG_PRIVATE_KEY_PASSPHRASE}"
+          cat 1> "${GPG_PRIVATE_KEY_FILE}" <<< "${GPG_PRIVATE_KEY}"
+          gpg --batch --yes --passphrase-fd 0 --import "${GPG_PRIVATE_KEY_FILE}" <<< "${GPG_PRIVATE_KEY_PASSPHRASE}"
+
+          # Export GPG keyring
+          gpg --batch --yes --export "${GPG_PRIVATE_KEY_FINGERPRINT}" 1> "${HOME}/.gnupg/pubring.gpg"
+          gpg --batch --yes --passphrase-fd 0 --export-secret-keys "${GPG_PRIVATE_KEY_FINGERPRINT}" 1> "${HOME}/.gnupg/secring.gpg" <<< "${GPG_PRIVATE_KEY_PASSPHRASE}"
 
       - uses: actions/checkout@v6.0.2
         with:
@@ -28,9 +77,10 @@ jobs:
 
       - name: Extract meta information
         run: |
+          echo "GITEA_SERVER_HOSTNAME=$(echo "${GITHUB_SERVER_URL}" | cut --delimiter '/' --fields 3)" >> $GITHUB_ENV
           echo "PACKAGE_VERSION=${GITHUB_REF#refs/tags/}" >> $GITHUB_ENV
-          echo "REPOSITORY_NAME=$(echo ${GITHUB_REPOSITORY} | cut -d '/' -f 2 | sed --regexp-extended 's/-charts?//g')" >> $GITHUB_ENV
-          echo "REPOSITORY_OWNER=$(echo ${GITHUB_REPOSITORY} | cut -d '/' -f 1)" >> $GITHUB_ENV
+          echo "REPOSITORY_NAME=$(echo ${GITHUB_REPOSITORY} | cut --delimiter '/' --fields 2 | sed --regexp-extended 's/-charts?//g')" >> $GITHUB_ENV
+          echo "REPOSITORY_OWNER=$(echo ${GITHUB_REPOSITORY} | cut --delimiter '/' --fields 1)" >> $GITHUB_ENV
 
       - name: Update Helm Chart version in README.md
         run: sed -i -E "s/^CHART_VERSION=.*/CHART_VERSION=${PACKAGE_VERSION}/g" README.md
@@ -38,24 +88,76 @@ jobs:
       - name: Package chart
         run: |
           helm dependency build
-          helm package --version "${PACKAGE_VERSION}" ./
+          helm package \
+            --sign \
+            --key "$(gpg --with-colons --list-keys "${GPG_PRIVATE_KEY_FINGERPRINT}" | grep uid | cut --delimiter ':' --fields 10)" \
+            --keyring "${HOME}/.gnupg/secring.gpg" \
+            --passphrase-file "${GPG_PRIVATE_KEY_PASSPHRASE_FILE}" \
+            --version "${PACKAGE_VERSION}" ./
 
-      - name: Upload Chart to ChartMuseum
+      - uses: docker/login-action@v4.1.0
+        with:
+          registry: ${{ github.server_url }}
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GIT_CRYPTIC_SYSTEMS_PACKAGE_REGISTRY_TOKEN }}
+
+      - name: Upload Chart to Gitea (OCI)
         env:
+          COSIGN_PASSWORD: ${{ secrets.COSIGN_PASSWORD }}
+          COSIGN_PRIVATE_KEY: ${{ secrets.COSIGN_PRIVATE_KEY }}
+        run: |
+          helm push ${REPOSITORY_NAME}-${PACKAGE_VERSION}.tgz oci://${GITEA_SERVER_HOSTNAME}/${REPOSITORY_OWNER}
+          cosign sign --yes --upload=true --key=env://COSIGN_PRIVATE_KEY ${GITEA_SERVER_HOSTNAME}/${REPOSITORY_OWNER}/${REPOSITORY_NAME}:${PACKAGE_VERSION}
+
+      - name: Upload Chart to Gitea (Helm)
+        env:
+          GITEA_REGISTRY_TOKEN: ${{ secrets.GIT_CRYPTIC_SYSTEMS_PACKAGE_REGISTRY_TOKEN }}
+        run: |
+          curl \
+            --fail \
+            --show-error \
+            --request POST \
+            --user "${REPOSITORY_OWNER}:${GITEA_REGISTRY_TOKEN}" \
+            --upload-file "${REPOSITORY_NAME}-${PACKAGE_VERSION}.tgz" \
+              https://${GITEA_SERVER_HOSTNAME}/api/packages/${REPOSITORY_OWNER}/helm/api/charts
+
+          # NOTE:
+          # Gitea does currently not support uploading Helm chart provenance files, so we skip this step for now. Once
+          # Gitea supports this, we can simply uncomment the following lines to upload the provenance file as well.
+          #
+          #   https://github.com/helm/helm/issues/31866
+          #
+          # if [ -f "${REPOSITORY_NAME}-${PACKAGE_VERSION}.tgz.prov" ]; then
+          #   curl \
+          #     --fail \
+          #     --show-error \
+          #     --request POST \
+          #     --user "${CHARTMUSEUM_USERNAME}:${CHARTMUSEUM_PASSWORD}" \
+          #     --upload-file "${REPOSITORY_NAME}-${PACKAGE_VERSION}.tgz.prov" \
+          #       https://${GITEA_SERVER_HOSTNAME}/api/packages/${REPOSITORY_OWNER}/helm/api/prov
+          # fi
+
+      - name: Upload Chart to Chartmuseum (Helm)
+        env:
+          CHARTMUSEUM_HOSTNAME: ${{ vars.CHARTMUSEUM_HOSTNAME }}
+          CHARTMUSEUM_USERNAME: ${{ secrets.CHARTMUSEUM_USERNAME }}
           CHARTMUSEUM_PASSWORD: ${{ secrets.CHARTMUSEUM_PASSWORD }}
           CHARTMUSEUM_REPOSITORY: ${{ vars.CHARTMUSEUM_REPOSITORY }}
-          CHARTMUSEUM_USERNAME: ${{ secrets.CHARTMUSEUM_USERNAME }}
-          CHARTMUSEUM_HOSTNAME: ${{ vars.CHARTMUSEUM_HOSTNAME }}
         run: |
-          helm repo add --username ${CHARTMUSEUM_USERNAME} --password ${CHARTMUSEUM_PASSWORD} chartmuseum https://${CHARTMUSEUM_HOSTNAME}/${CHARTMUSEUM_REPOSITORY}
-          helm cm-push ${REPOSITORY_NAME}-${PACKAGE_VERSION}.tgz chartmuseum
-          helm repo remove chartmuseum
+          curl \
+            --fail \
+            --show-error \
+            --request POST \
+            --user "${CHARTMUSEUM_USERNAME}:${CHARTMUSEUM_PASSWORD}" \
+            --upload-file "${REPOSITORY_NAME}-${PACKAGE_VERSION}.tgz" \
+              https://${CHARTMUSEUM_HOSTNAME}/api/${CHARTMUSEUM_REPOSITORY}/charts
 
-      - name: Upload Chart to Gitea
-        env:
-          GITEA_PACKAGE_REGISTRY_TOKEN: ${{ secrets.GIT_CRYPTIC_SYSTEMS_PACKAGE_REGISTRY_TOKEN }}
-          GITEA_SERVER_URL: ${{ github.server_url }}
-        run: |
-          helm repo add --username ${REPOSITORY_OWNER} --password ${GITEA_PACKAGE_REGISTRY_TOKEN} gitea ${GITEA_SERVER_URL}/api/packages/${REPOSITORY_OWNER}/helm
-          helm cm-push ${REPOSITORY_NAME}-${PACKAGE_VERSION}.tgz gitea
-          helm repo remove gitea
+          if [ -f "${REPOSITORY_NAME}-${PACKAGE_VERSION}.tgz.prov" ]; then
+            curl \
+              --fail \
+              --show-error \
+              --request POST \
+              --user "${CHARTMUSEUM_USERNAME}:${CHARTMUSEUM_PASSWORD}" \
+              --upload-file ${REPOSITORY_NAME}-${PACKAGE_VERSION}.tgz.prov \
+                https://${CHARTMUSEUM_HOSTNAME}/api/${CHARTMUSEUM_REPOSITORY}/prov
+          fi
diff --git a/.gitignore b/.gitignore
index 712fa4a..f7ffbb9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 charts
+cosign*
 node_modules
 target
 !values.yaml