How to prove you created something first � a post-quantum notary

If you invent something, write something, or design something, the value often depends on one question: can you prove you had it first? Patent disputes, copyright claims, trade-secret cases, and even academic priority all turn on demonstrable proof-of-priority. The usual tools are weak in a specific way: a notary stamps a document with an ECDSA or RSA signature and a timestamp, but those classical signatures become forgeable once large quantum computers exist � exactly the multi-decade horizon over which intellectual property must stay defensible. A proof you can no longer trust in 15 years is not much of a proof.

A post-quantum notary fixes the durability problem at its root. You hash your artifact (the document, the design file, the source code) and sign the hash with a post-quantum signature � Dilithium-2, NIST FIPS 204 � together with a timestamp anchored to a public, verifiable reference such as a blockchain block or a public randomness beacon. The signature proves the artifact existed in that exact form at that time and was authorized by your key, using a scheme resistant to all known classical and quantum attacks. Change a single byte of the artifact and the hash no longer matches; the certificate is self-verifying and anyone can check it without trusting you or the notary.

Be precise about what this does and does not establish. It proves that a specific artifact existed and was sealed at a specific time � a strong anchor for priority. It does not adjudicate authorship disputes, prove originality, or replace a lawyer or a patent office; it is evidence, not a verdict. And no signature scheme is secure forever � this is the standard worth building on today, not a permanent guarantee. For inventors, researchers, and creators who need their proof to still hold up decades from now, sealing it with a post-quantum notary the moment it exists is the rational move.