garlicoin.orgProve a file existed
Put a file's fingerprint on the Garlicoin chain, so anyone can later check it existed by then. Your file never leaves your device. 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
Keep the file exactly as it is: one changed byte, even from re-saving, gives a different fingerprint.
What a proof shows
- That this exact file existed by a date. Nobody can backdate a block.
- Not who made it, or what's inside. You can prove private documents without showing them.