Verify · ECDSA P-256
Verify Signed Content
Independently verify cryptographically signed posts.
About This Tool
This page allows you to independently verify that content was signed by the author's private key. You can paste content directly, upload a downloaded signed-post file, or verify using OpenSSL commands.
Upload a signed-post.txt file downloaded from a blog post:
No file selected
Manual Verification with OpenSSL
For maximum trust, verify signatures using your own tools without relying on this website's JavaScript:
Step 1: Save the content
Copy the original signed content (markdown) and save it to a file:
echo -n "YOUR_CONTENT_HERE" > message.txt
Step 2: Save the signature
Copy the Base64 signature and save it:
echo "BASE64_SIGNATURE" > signature.b64
Step 3: Download the public key
Download from: /public_key.pem
curl -o public_key.pem https://example.com/public_key.pem
Replace example.com with your deployed domain, or use a relative path if verifying locally.
Step 4: Decode the signature
base64 -d signature.b64 > signature.bin
Step 5: Verify
openssl dgst -sha256 -verify public_key.pem -signature signature.bin message.txt
If valid, you'll see: Verified OK
Important Notes
- The signature covers the original markdown, not the rendered HTML
- Whitespace and newlines must match exactly
- Use
echo -nto avoid adding extra newlines - The signing algorithm is ECDSA with SHA-256 on curve P-256 (prime256v1)