Blockchain Notary

Prove ownership on the Bitcoin Blockchain

Get Started

Drag a file into the browser window. Your file will not be uploaded to our server. Learn more.

Document Privacy

Your file never leaves your computer. Rather, your web browser computes the cryptographic hash of your file, and that is the only data sent to us. We know nothing about the contents of your document.

How it works

  1. Add your file by dragging it into the browser or using the file selector above.
  2. Follow the prompt to send bitcoin and fund your blockchain anchor.
  3. See your proof on the blockchain by checking the transaction in a block explorer.

Be your own Notary

Prove timestamped existence of a document without trusted third parties.


Historically, governments acted as trusted third parties by issuing important life documents (like property titles, drivers licenses, and birth certificates).

Pre-bitcoin document proof was characterized by Greco-Roman columns, long lines, unpleasant demeanors, ceremonial vestments, and poor building maintenance.

Today, these roles can be automated.


With Notary, you can create your own universal timestamped proof of a document's existence.

A cryptographic digest of your document will be stored in the bitcoin blockchain, linking it to the time of submission.

Your document could be anything, from an input-constrained form like conventional government documents to a full-resolution movie or location-stamped image.


Trustlessly backing up important documents allows you to prove existence even when an official version goes missing.

You control your own information — your document's contents are not stored in the blockchain or ever exposed.

Prove your document existed by comparing the blockchain entry of your document's cryptographic digest to your actual document (if and when the need arises).


Prove data ownership

In most jurisdictions, applying for a patent or proving ownership of copyrighted material involves unpleasant (and wildly expensive) third parties. With Notary, you can prove ownership of information at a given time without revealing the actual information.

Example 1: United States Patent Office versus personal use of Notary


U.S. Patent Office


Costs more than $10,000 USD and takes more than a year to process
Can only be upheld by expensive third parties in robes
Immediate, inexpensive confirmation
Trivially upheld by supra-legal mathematical postulates
Participation is voluntary

Prove data integrity

Some documents, like property titles, have important consequences linked to changes in the document over time. You can use Notary to prove that a document has existed in an unchanged form. Prove your document did not change by matching your file's cryptographic digest at some future date to the one you stored in the blockchain with Notary.

Example 2: Conventional Title Insurance versus personal use of Notary


Title Insurance


Costs about $5,000
Mostly exists to promote illusion of ownership
Ultimately subject to political climate
May be violently over-ruled, but never deleted or disproven
Participation is voluntary

Prove data existed at a certain time

The bitcoin blockchain is globally distributed and requires proof of work to update. Your submission forever proves the existence of your document in its current state at the time of your submission.

Example 3: Government-issued Birth Certificate versus selfie with infant, added to Notary


Birth Certificate


Physically degrades with time
Can only be accessed by calling parents, waiting, and hoping
Validity depends on trusted issuer
Immutable; permanently and privately accessible from your phone
Participation is voluntary

Practical considerations

In most of the world, humans are still required to participate in multiple forms of conventional document proof. As reputation and identity become key components of the digital world, the existence of a voluntary alternative will support information privacy and ownership.

Recent documents registered

  Document Hash Timestamp
da503feb4e25e263​b6964851863ffc62​d43c45dd5fbab24b​0f3aba64da393ed0 2017-06-23 18:00:30 UTC
ba3e44685f1cd76c​e0c4175fe43c6070​c600fd2c4179303f​d3dd568a99428118 2017-06-23 11:27:41 UTC
010d39f181b7495e​f382743f512d4541​4af4beba63cd10a5​a1de61d01e4daa49 2017-06-23 11:25:47 UTC
2aa9da14739de2b0​69a3eeb0a4427dcf​ffdd88eb3e61f6e8​55d04f8c75ed7361 2017-06-23 11:03:13 UTC
be33f6b6f255cc5a​b93002f261cb506b​d7539e2a23b8655d​791855fb36674fce 2017-06-23 11:02:57 UTC

Recent blockchain anchors

  Document Hash Timestamp
2c7d4626b8a01a72​762c54cf93be648b​153d583f53dfcbfb​72c537814f340605 2017-06-22 16:25:30 UTC
aba6dda6416346c4​29b7f27c84b34f29​dc587c476572600a​bbfe5798decdc44d 2017-06-06 06:54:37 UTC
1c4d2ec5552f6d46​269c79cec4f3225d​12cb4aa511809d7f​54c1ef032207c524 2017-06-05 05:37:21 UTC
94e9cb55ccb7537c​40d0f2d3159a4177​3020b18fb5b839a3​500dfb7326084fd0 2017-05-06 20:23:30 UTC
bbcc7cc29ff0862e​4c7b4c662a78d090​124c54a5e925d8ab​7a112ed3d4218586 2017-05-02 18:47:47 UTC
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