⛓ On-chain · Immutable · Quantum-resistant

Proof of
Existence.

Permanently timestamp any document, file, or text on the VoidCoin blockchain. Prove your content existed at a specific point in time — forever.

01
Choose your content. Upload any file (PDF, image, contract, source code, photo) or paste any text. The SHA256 fingerprint is computed entirely in your browser — your content is never uploaded or transmitted anywhere.
02
Sign with your wallet. Enter your seed phrase (web wallet) or WIF private key (Qt wallet). Your key never leaves the page. A transaction is built and signed locally, embedding the hash in an OP_RETURN output for a tiny fee of ≈0.0001 VOID.
03
Download your certificate. Once confirmed on-chain, download your proof certificate. Anyone can verify your proof forever — just hash the original file and check the transaction on the explorer.
Full instructions
What you need
  • › A VoidCoin 3... address with at least 0.001 VOID confirmed balance
  • › Your seed phrase (from wallet.void-coin.net) OR your WIF private key (from Qt wallet)
  • › The file or text you want to timestamp
How to export your WIF key (Qt wallet)
  1. Open VoidCoin-Qt
  2. Go to Help → Debug Console
  3. Type: dumpprivkey YOUR_3_ADDRESS
  4. Copy the WIF key and paste it below
How verification works

When you stamp a document, the SHA256 hash of your file is embedded in a VoidCoin transaction's OP_RETURN field. This creates a permanent, immutable, timestamped record on the blockchain. Anyone can verify your proof at any time by: hashing the original file with SHA256 → looking up the transaction ID on explorer.void-coin.net → confirming the OP_RETURN field contains 6a20 followed by your hash. The block timestamp proves your document existed at or before that moment in time — forever.

Use cases
Legal documents
Contracts, agreements, wills — prove a document existed and was unmodified before a dispute arises
Creative work
Music, art, writing, code — timestamp your intellectual property before publishing
Research & evidence
Scientific data, journalistic evidence, photos — prove authenticity and chain of custody
📄 File
📝 Text
📁
Drop any file here or click to browse
PDF, DOCX, image, contract, source code — any file type
VOIDCOIN
Proof of Existence Certificate
Document Timestamped
This certificate proves that the described document existed and was hashed at the time of the VoidCoin transaction below. The proof is permanent, immutable, and verifiable by anyone.
void-coin.net/proof.html VoidCoin blockchain · SHA-256 · OP_RETURN
View on explorer ↗
Verify an existing proof
Have a document and a transaction ID? Verify the proof instantly. Upload the original file (or paste original text) and enter the transaction ID to confirm the hash matches what's on-chain.
Verify proof
Or use the hash from the document above