garlicoin.orgProve a file existed
Put a file's fingerprint on the Garlicoin chain, so anyone can later check that this exact file existed by then. Your file never leaves your device: only its SHA-256 fingerprint is written. It costs 1 GRLC, and all of it goes to the faucet.
Already have a SHA-256 fingerprint? Paste it
Your file
Proven on the chain
Check it with your own node
The transaction has an OP_RETURN output holding 4752 4c43 5052 4f4f 4601 ("GRLCPROOF" and a version byte) followed by the fingerprint. Hash your copy of the file with sha256sum and compare.
Not on the chain yet
Prove that this file existed today. Keep the file exactly as it is: changing even one byte gives a different fingerprint.
What a proof shows
- That this exact file existed by a date. The block's time stamps it. Nobody can backdate a block, so nobody can fake an older proof.
- Not who made it. A proof says the file existed, not who wrote it. Keep your drafts and notes if authorship matters.
- Nothing about what's inside. A fingerprint can't be turned back into the file, so you can prove private documents without showing them.
- Only for the exact bytes. Re-saving, converting or editing the file changes its fingerprint. Keep the original.
Good for: art and writing before you share it, contracts and agreements, code releases, predictions, research data.