diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index abb0691..e08d5a3 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -468,18 +468,19 @@ jobs:
             1>${{ env.TARGET_LIBRARY == 'onnxruntime' && '&1' || format('{0}_stdout.txt', matrix.artifact_name) }} \
             2>${{ env.TARGET_LIBRARY == 'onnxruntime' && '&2' || format('{0}_stderr.txt', matrix.artifact_name) }}
 
-      - name: Send build log to Discord
+      - name: Encrypt the build log
         if: failure() && steps.build.outcome == 'failure' && env.TARGET_LIBRARY == 'voicevox_onnxruntime'
         run: |
-          curl \
-            "$PRODUCTION_DISCORD_WEBHOOK" \
-            -sf \
-            -F 'payload_json={"username":"onnxruntime-builder"}' \
-            -F file1=@${{ matrix.artifact_name }}_stdout.txt \
-            -F file2=@${{ matrix.artifact_name }}_stderr.txt \
-            > /dev/null 2>&1
-        env:
-          PRODUCTION_DISCORD_WEBHOOK: ${{ secrets.PRODUCTION_DISCORD_WEBHOOK }}
+          for file in ./${{ matrix.artifact_name }}_{stdout,stderr}.txt; do
+            gpg -ef ./builder/build-log-pk.asc "$file"
+          done
+
+      - name: Upload the encrypted build log
+        if: failure() && steps.build.outcome == 'failure' && env.TARGET_LIBRARY == 'voicevox_onnxruntime'
+        uses: actions/upload-artifact@v4
+        with:
+          name: buildlog_${{ matrix.artifact_name }}
+          path: ${{ matrix.artifact_name }}_*.txt.gpg
 
       - name: Inspect the build directory for debug
 
diff --git a/build-log-pk.asc b/build-log-pk.asc
new file mode 100644
index 0000000..aba3ed6
--- /dev/null
+++ b/build-log-pk.asc
@@ -0,0 +1,14 @@
+-----BEGIN PGP PUBLIC KEY BLOCK-----
+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+=IosB
+-----END PGP PUBLIC KEY BLOCK-----