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
c4bca7816435462d​4caf98bc9a15efe5​064ef17f0e181d57​d7fd5dcece93c64b 2017-05-23 22:11:36 UTC
6db9b75bafc9e650​8ae014d019b5b46b​09ab85eee4237c79​9e780304e344c023 2017-05-22 12:10:42 UTC
68d3be249c7bf917​7f2d364e37ac46bf​02c68295b6da591f​9ff50472dd219452 2017-05-22 01:37:08 UTC
a5e14536c560aafe​f66863885278c030​14ff39c46fb8cea0​835595f623ff74c7 2017-05-21 12:04:29 UTC
fe0475b465a0504e​a9bca80c4be344c5​e221b6cf2a6bc92e​5102d3e125bd7f8d 2017-05-20 18:06:20 UTC

Recent blockchain anchors

  Document Hash Timestamp
94e9cb55ccb7537c​40d0f2d3159a4177​3020b18fb5b839a3​500dfb7326084fd0 2017-05-06 20:23:30 UTC
bbcc7cc29ff0862e​4c7b4c662a78d090​124c54a5e925d8ab​7a112ed3d4218586 2017-05-02 18:47:47 UTC
cd1a08cb6b2b4e8b​9f5793ff02416cb5​9df8507aabe9487e​9e6eafe4cafaa45d 2017-05-01 02:30:42 UTC
47a066a5f73c9af8​39a8c231124496f9​277e5910c0237ce3​e6313e6dce1c903b 2017-05-01 02:30:42 UTC
a733dec2d0fae08e​966f63666e88a889​9b136e150aea16da​eb3807641610b8f7 2017-04-15 21:26:26 UTC
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