the file never leaves this browser. only its hash does.
drag anything here, or click to choose
a document, a recording, a photograph, a promise
Not-before: this artifact's hash, quoted with the current block, proves it could not have existed before that block. Not-after: the OTS receipt, once anchored, proves it existed before a later block. Identity is optional — sign the digest with any key you keep (Nostr, PGP, SSH), or seal anonymously. The bracket holds either way.