Creators & inventors

“I need to prove I had this first, without publishing it.”

Prove you made it first. Keep it to yourself.

Identity is self-declared. This is not a third-party or qualified (QTSP) notarization.

Request alpha access →Invite-only during the alpha. The people who sign need no account.

How it works

  1. Drop your file; it never leaves your device.
  2. Take your photo with the file's code in frame.
  3. Your record is anchored to Bitcoin and verifies offline.

A Bitcoin timestamp nobody, including COSigna, can move.

What COSigna does not do

It dates a file; it does not prove who created it. It is not a patent filing, nor a notary's act.

Request alpha access →Invite-only during the alpha. The people who sign need no account.
COSigna — patent EP3665600B1 · US11531746B2 · FR3070079B1
Report bugCOSigna — a Cryptographic Ring of Mutual Consent · The ring is strong because the loop is closed.The ring is strong because the loop is closed.COSigna