Cuervia: Timestamp Your Work

Seal the date of your work with OpenTimestamps and Bitcoin. The fingerprint is computed on your iPhone and the file is never uploaded. No account, no subscription.

Your work, with a proven date: Cuervia computes its SHA-256 fingerprint inside your iPhone and seals it in Bitcoin with OpenTimestamps. No account, no payments, and your file is never uploaded.

You pick a file and, from that moment on, you hold proof of prior existence that anyone can check independently, with public tools and without going through us.

YOUR FILE NEVER LEAVES YOUR IPHONE The original is never uploaded. The only thing that travels is 32 bytes: the fingerprint. A fingerprint cannot be used to reconstruct your work, but it can prove that a file is exactly the one that was sealed.

THE PROOF DOES NOT DEPEND ON US The seal is stored as a standard .ots file that you can export and verify with the official OpenTimestamps tools. If Cuervia disappeared tomorrow, your proof would still hold. That is precisely what makes it worth something.

WHAT IS INCLUDED Work certification with a SHA-256 fingerprint computed on device, in chunks, with no practical size limit. Real OpenTimestamps seal anchored in Bitcoin. Hash-chained evidence record: every event points to the previous one, so later tampering is detectable. PDF certificate ready to show a client, a platform or your lawyer. Full evidence export bundling the certificate, the .ots seal and a manifest. Local verifier: pick a file and we tell you whether it matches one of your works. Optional Face ID to protect the record. Works offline: the fingerprint is computed anyway and the seal is sent once you are back online.

WHO IT IS FOR Illustrators, photographers, designers, writers, musicians and anyone who produces original work and wants the date on record.

NO ACCOUNT, NO SUBSCRIPTION, NO ADS There is no sign up, no in-app purchases and no advertising. We use no advertising identifier. The app ships a single third-party SDK, Firebase Analytics in its variant without ad identifier support, and it only runs if you turn on usage diagnostics in Settings: it is off by default and never sends titles, file names or fingerprints.

WHAT IT DOES NOT DO Cuervia attests that a file with a given fingerprint existed on a date and has not been altered since. It does not attest ownership, it is not an intellectual property registry and it is not a substitute for legal advice.