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
c50324d85b8447ff​af74109ad57db8cc​dffbff3a1d206d34​55d1e7133d5a6569 2017-10-20 09:59:11 UTC
d619fb00dd47d31c​790c800d571b9008​4aa427b83f2e08e1​04bbb330b84ca2f6 2017-10-20 01:00:22 UTC
f54954c108a13668​8fb6c220b82ab81c​f978ea2be555e406​048749bdccdd63fc 2017-10-18 19:51:39 UTC
f5a3a0721e7337de​186e466a54263ddd​5d463afc751eef02​7f3b4c5823000c80 2017-10-18 16:11:30 UTC
11653525be37760c​d10c6ea7a0c986fd​a695020795abf7d0​ad10f9cab1c09221 2017-10-18 06:20:13 UTC

Recent blockchain anchors

  Document Hash Timestamp
76f5c9d19df345eb​89e3784adfab0da7​e933c6a4ae3c831b​a9554c2d345083da 2017-09-18 04:13:54 UTC
49572e077fa9b178​f4977ccc402217d7​5966ce2749735cec​66835ed6e79e293d 2017-09-17 10:07:28 UTC
c0aea2411c6766c1​449023a4fde25d3e​573b23d5b3918db3​1c9b59ec1b697b30 2017-09-16 16:31:25 UTC
ffd8fc8741e69717​275b39bbe544d444​14f3b29206a15858​5b9d32978c296a3a 2017-09-11 12:43:09 UTC
dda4d50af53b6d1a​4684754ac6150a74​d2187247256a08e6​8d37432f6b588a62 2017-09-11 12:24:25 UTC
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