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
3257506d17dd5c3f​2fafc181998c995f​809954b6c159798b​e1b63437c5e41bbb 2017-08-24 04:59:57 UTC
4cf1165702e9c143​b0490aa2e41beee4​48d39f1e6093ec6f​17b988f98c3bffb4 2017-08-23 18:30:31 UTC
cf646e8c4beeba41​a4ba5d84c453cf56​7a7b11794823918c​731406886dd67e7b 2017-08-23 10:16:08 UTC
1483084b0bd90714​578ef31e331c46f2​db71b00aa5aac5b5​6700f8f17a2b09b5 2017-08-23 07:07:56 UTC
949cb289cd3daeaa​c0dd969e714f0368​1ca73e0c5e2d91fb​fca149ab556853ef 2017-08-22 15:05:06 UTC

Recent blockchain anchors

  Document Hash Timestamp
3c3cf48736f7f32f​b6aca650819d674f​fd3a926757429c8b​0fbfc132aac6b5b0 2017-08-23 22:02:38 UTC
7966ba41450b077e​d803ae320e3344b3​ef4eb274648f6c3e​ed2197bb012d452a 2017-08-23 22:02:38 UTC
bceddb0fc0f20506​b5a0442e670bf584​f46e61d7d68d25af​1c08a9a55e3c3c46 2017-08-23 22:02:38 UTC
1483084b0bd90714​578ef31e331c46f2​db71b00aa5aac5b5​6700f8f17a2b09b5 2017-08-23 22:02:38 UTC
64e4c04fd279f4c0​82cab0fdc444a831​84f3b1cdf14b028e​20cb7da222367830 2017-08-08 12:17:40 UTC
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