How to Use and Verify Blockchain Timestamp

What is BlockchainSign.io

Think of BlockchainSign.io like a digital notary that proves when you created a document. Just like a notary stamps papers to prove they're real, we use blockchain technology to create a permanent, unchangeable record of your file.

How it works

  1. You send us your file - We take your document, image, or any digital file
  2. We create a "fingerprint" - We use SHA256 math to create a unique code (called a hash) for your file's information
  3. We save it to the blockchain - This fingerprint gets permanently stored on Ethereum blockchain
  4. You get a certificate - We give you a certificate file that proves everything

What is a SHA256 fingerprint?

The "fingerprint" is actually a SHA256 hash of your payload data (the information section in your certificate). SHA256 is a special mathematical formula that turns any text into a unique 64-character code. Even changing one letter would create a completely different hash!

What you receive

You'll get a certificate file (like cert.yml) that contains:

  • Your file's information (email, file details, etc.)
  • Blockchain transaction ID - The permanent record number
  • Link to view it online - So anyone can check it's real

How to verify your certificate is real

Step 1: Open the blockchain link

In your certificate, find the line that says tx_url.

For example: https://etherscan.io/tx/0x1833eb71a350493c32b7e828b56308bd16fe117d5a6ab49139a666dad9683f6f

Click this link - it will take you to Etherscan.io (think of it like Google for blockchain transactions).

Step 2: Find the hidden data

On the Etherscan page, you need to find the actual data that was stored:

  1. Look for a section called "More Details"
  2. Find "Input Data"
  3. Click "View as UTF-8" (this makes the computer code readable)

Step 3: Check the fingerprint matches

In the readable data, you'll see a hash (long string of letters and numbers). Compare this with the payload_hash in your certificate - they should match exactly!

How to verify the SHA256 hash yourself

You can double-check our work by generating the SHA256 hash yourself using any online SHA256 calculator:

Step 1: Copy your payload data

From your certificate, copy everything under the payload: section. For example:

  Email: [email protected]
  File SHA-256: a0566e5c4d077424a7be39d95d1308488c81b7b49274588bf9f5b2eb13554ac4
  Meta: Example Tech Solutions LLC

Step 2: Remove leading spaces

IMPORTANT: Since the certificate is in YAML format, you need to remove the leading spaces from each line. The text should look like this:

Email: [email protected]
File SHA-256: a0566e5c4d077424a7be39d95d1308488c81b7b49274588bf9f5b2eb13554ac4
Meta: Example Tech Solutions LLC

Step 3: Generate SHA256 hash

  1. Go to any online SHA256 generator (like https://emn178.github.io/online-tools/sha256.html)
  2. Paste your cleaned payload text
  3. Generate the hash
  4. Compare it with the payload_hash in your certificate - they should match exactly!

This proves that the data in your certificate is exactly what was timestamped on the blockchain.

Why this proves your file is real

  • Blockchain is permanent - Once something is on the blockchain, it can never be changed or deleted
  • Timestamped - The blockchain shows exactly when we saved your file's fingerprint
  • Public verification - Anyone in the world can check Etherscan to verify your certificate is real

Need help?

If you're having trouble verifying your certificate, contact us at [email protected]

BlockchainSign.io

This service uses Ethereum blockchain and SHA-256 cryptographic hashing for maximum security and permanence.

Back to Home