Quadrans Foundation provides a free notarization service. This tool can timestamp a document, prove its integrity and ownership of the document at the time the timestamp occurred.

Subscribe to our service for free, then follow simple steps outlined in the how-to. Please make sure you read and fully understand the FAQ and the disclaimer of this service.


The service provided by Quadrans Foundation issues unique digital timestamping of documents upon request from users.
Any legal repercussion varies according to the legislation of the Country in which this service is used.
Unless recognised by the statutory law of the Country in which this service is used and a clear reference to the legislation is made, the service provided by Quadrans Foundation does not override the legal authority of a government official or a qualified person who is legally appointed to provide services recognised by the State.



It couldn't be simpler

Chose the document/file you want to notarize. If you want to notarize multiple files at once collect all the data into an archive (like a .zip or .tar file). Then, using a hash calculator, get the SHA256 digest of the file or archive.
The rest of the process is done via email: send an email to following the simple instructions below:
  • To:
  • Subject: must contain the word "notarize" (case insensitive)
  • Body: must contain a valid SHA256
... and that's it !

As simple as that: example of an email sent from gmail to notarize the message "hello"

Then what?

You will receive a response via email within minutes. It might either say that your request has been queued or, in case an error occurs, that your request has been rejected. Depending on the amount of requests we receive it might take up to 24 hours. Please be patient, do not send the same request twice while waiting for the completion of the first request.

The response email will contain a short description and will carry a PDF file as attachment. Print or save the PDF file and store it together with the original document/data in a safe place. Those two elements are required to prove the integrity of the notarization. In the PDF file you will find a QRCode that points to a courtesy page on Quadrans website. This page contains the same information of the PDF file structured in a step-by-step procedure allowing an independent verification of all data.

Please take your time to get familiar with the procedure and test out all the steps involved.



The only programs you need for the notarization process are an email client and a hash calculator tool to compute the SHA256 hash of the file you want to notarize. Several free tools are available for the different Operating Systems.



Here is a list of some frequenty asked questions. If you have a doubt you will probably find and answer hereunder. Should this not be the case, please send us an email and we'll reply to you and update the FAQ list.

Q) Can I just send the file instaed of it's hash?

A) No, you don’t want that… The main reason for this is your security. Sending importand documents, intellectual property or sensitive data, via Internet is never a good idea. Anything can happen along the way and result in (as an example, but not limited to) personal data breach such as stealing your data and/or notarize it using third parties’ name or having the service denied. Be wary, only send hashes to any notarization service provider. Also, this unnecessarily make the service more complex. For example there could be a limit in the size of data the service can handle, or people handling the data (directly or indirectly) need to be authorized to properly handle data.

Q) Is there a limit to the size of the document/data I can notarize?

A) No, since you are required to compute the hash offline. All SHA256 hashes result in a 64 characters string, whether it comes from a short sentence or a database dump of several terabytes, so the size of the original document/data to notarize is not a concern.

Q) Are there any limitations or restrictions on the type of document/data I can notarize?

A) No. The SHA256 algorithm treats your data as a continuous finite stream of bytes and ignores the content. Just remember that the document shall never be changed once it’s notarized. Changing a single bit in the file would void the entire notarization process. Some software (spreadsheets, word processors) might change the file if you open it (autosave, updates, statistics, metadata etc). Keep the original file you used for the hash in a safe place and never overwrite it. If you need to make changes, we suggest to work on copies. In general, zip files and PDFs are the most suitable for this purpouse.

Q) Are there any limitations on the number of notarizations I can do?

A) Yes. Since this is a free service, the access to this resource is reguated to discourage inappropruiate use. Currently each registered user can perform a maximum of one notarization per day.

Q) Can I notarize an encrypted document?

A) Sure! You can encrypt the document and then calculate the hash of its’ encrypted version, since the content of the file does not affect the SHA256 algorithm. Just note that this might be unnecessary, since it is impossible to revert the hash procedure and retrieve the content of the original file from the hash. On the other hand it is advisable to encrypt the document if it contains sensitive data and/or if you plan to store it into an online/cloud service (like Dropbox, Amazon S3, etc).

Q) Do you store the file/data/documents for me?

A) No. Quadrans Notarization is a free service and we cannot keep a copy of every document/data we notarize, plus it’s insecure. The user of the service shall keep the original copy of the notarized data in a safe place along with the documents received that prove the notarization took place. These elements can be used to prove data integrity, timestamp and ownership.

Q) The hash in the documents I received is not the same hash I submitted !

A) Exactly. In order to deal with a great amount of data in total security and privacy, Quadrans Notarization makes extensive use of Merkle Trees and hashes. What gets written on the Quadrans Blockchain is the root of the Merkle Tree, and the tree is composed pairing the ‘evidences’ of the submitted hashes. In other words: your hash and email address are used to derive a unique ‘evidence’, then ‘evidences’ of many other documents are collected in a Merkle Tree and the root of that Merkle Tree is written in the Blockchain

Q) What is the 'evidence' of a document/data ?

A) Quadrans Notarization service notarizes the hash you submitted, as well as the fact that it actually was sent from your email address. Firstly we compute the hash of the sender’s email address (a string) using SHA256. Then the hash submitted and the hash of the email address are concatenated to form a 512-binary array. That binary array gets hashed twice with SHA256 to form the evidence. This way, Quadrans records that the document/data was sent from that email address, without revealing the contents of the document/data nor the sender’s email address.

Q) Does Quadrans notarization have legal validity in court ?

A) Legal aspects and implications of a blockchain notarization may vary according to legislation of the country you operate in. Some countries consider the timestamp obtained via the blockchain notarization legally valid, others don’t. Please seek professional advice to clarify any aspect that may concern legal implication an validity. Also, if you are using this notarization for a cross-border business, you might need to check on both countries as ther legislation is likely to have different approaches.



Please consult the laws of your country concerning notarization and blockchain. Remember that notarizing a document or packet of data does not mean that it's content or it's meaning is true. Also notarizing a document does not imply that you are the rightful owner of the document, but that you had a copy of it at the time it was notarized.

This is a free service and is provided "as-is". In no event Quadrans Foundation or the contributors are liable for any direct, indirect, incidental, special, exemplary, or consequential damages (included but not limited to procurement of substitute goods or services, loss of use, data or profits, or business interruption) however caused and in any theory of liability, whether in contract, strict liability, or tort (including negligence or otherwise) arising in any way out of the use of this service, even if advised of the possibility of such damage. No assumptions can be made about this service, included but not limited to for it's reliability or fitness for any particular purpose.


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