How does the blockchain authentication work ?

Any digital document wears a unique digital footprint. We first extract the digital footprint (the hash) of a document using the mathematical function SHA-256, an international standard. The “hash” can be represented by a single combination of 64 characters. Then, we use this specific footprint and anchor it into a Blockchain transaction.

Why certify documents ?

There is two types of distinct rights. The “registered rights” (pattern, brand) and the “unregistered rights” (copyrights, drawings and models, business secret…). The unregistered rights are not materialized by an official document certified by the country. Thus, it is very hard to justify their existence in front of a judge.


The risks are potentially strong though, and continuously growing : counterfeit, unfair competition, industrial espionage, cyber attack… Being aware of those risks and preventing them is fundamental, if you don’t want to lose months of hard work.

Why using the Blockchain instead of existing solutions ?


The Blockchain is a decentralized ledger, which offers a quick and simple authentication system by anchoring them on the chain (refer to the question “How does the Blockchain authentication work ?”). Moreover, it is by essence impossible to falsify the ledger and to modify the transactions, which offers a high level of confidence in the system. Then, it is an international standard, acknowledged all over the world, and its decentralization prevents losses. It offers an highly-competitive solution, compared to existing solutions.

What is the certification worth in front of a judge ?

In France, the Blockchain authentication establishes a “commencement of proof in writing”. Moreover since the European regulations eIDAS (23th July 2014), an evidence can’t be refused by a judge because it is of digital nature.

Then, the Blockchain authentication competes with the other types of evidence dedicated to copyrights (e-mail Soleau or online service of juridical protection). This allows proving in front of a judge the paternity, anteriority and integrity of a document.


In the US, the regulation towards Blockchain varies a lot depending on the states. The state of Vermont already “recognizes data stored on a blockchain as admissible in the court system” (Vermont Rule of Evidence 902).

Arizona, Illinois and Delaware went a step further, as they introduced or passed regulations making legally valid signatures, transactions and contracts stored on the Blockchain, and even “allowing residents to pay their income tax in cryptocurrencies”.

Eventually, there is now a case law in China, as the internet court of Hangzhou recognized as legally valid an evidence of Blockchain authentication, on the 28th June of 2018.

How to prove the authentication ?

The evidence is generated by putting together the original document and the footprint which has been extracted. If the original document is altered, so is the footprint.

In order to prove the authentication, the original document and the “ certificate of authentication ” delivered by Datatrust must be gathered. It will then be possible to link up the anchoring on the Blockchain.

Comment puis-je prouver que le document que vous certifiez m’appartient ?

Bien que la certification par la blockchain soit parfaitement opérationnelle et recevable par un juge, un challenge demeurait : prouver que le document certifié par Datatrust vous appartient. Afin de pallier ce problème nous avons mis en place la signature WebService, un mécanisme qui permet de faire le lien entre le document certifié et vous.

Quel est le fonctionnement de la signature WebService ?

La signature WebService est une signature cryptographique, qui permet à l’utilisateur de signer électroniquement le document avant de nous l’envoyer. Grâce à ce procédé, nous pouvons prouvons que nous certifions les documents pour le compte de nos clients. Et si demain nous étions amené à disparaître, grâce à la signature WebService, la parenté demeurerait.

What is the Flash offer ?

The Flash offer gives you the possibility to certify up to 250 digital documents every month. In exchange, we guarantee you that all the files will be certified within the 2 following minutes.

This offer is particularly interesting for the clients who face time constraints (e.g. press release).

What is the Unlimited offer ?

The Unlimited offer allows you to certify an unlimited number of files every month. These files will be certify within the next 24 hours, at one or multiples times previously settled.

It perfectly suits the companies having to certify a large number of files, without being especially compelled by time.

Is a mixed offer possible ?

Based on your individual requirements, we can build together a tailor-made offer. For instance, you might need to certify more than 250 files a month, however facing time constraints. In this case, the offer can be customised.

Can we integrate Datatrust into our existing tools ?

We can perfectly link the Datatrust API to your tools, so it is seamlessly integrated into an operating system. We invite you to notify us.

When can I terminate the subscription ?

You can terminate your subscription at any time, subject to a 90 day notice.

How can I certify a document ?

It is very easy to certify a document on Datatrust platform. First, click on the tab “Certify”. Drag and drop your file into the box “Drop a document” (you can add details if you desire), then click on “Certify”.


Your document will then appear directly into the list of certified documents in the tab “Documents & certificates”, if you chose the Flash offer.
In the case of the Unlimited offer, you will be able to find it into the box “Pending documents”, until it gets certified later.

How much time takes the authentication ?

It depends on the offer you’ve subscribed to. The authentication will take less than 2 minutes if you have chosen the Flash option. Regarding the Unlimited option, all the documents will be certified at one or various time of the day (following what you have decided).

What about certifying confidential documents ?

You can certify anything without the content of the document being disclosed. The footprint, a unique combination of 64 characters, doesn’t include any data related to the document itself, nor can’t lead to the informations contained.

What file format can I certify ?

All the formats are accepted (.pdf, .png, .jpeg, .gif…) and can be certified. You just need to drag the file on the platform.

May I certify a .ZIP file ?

Yes, you can certify a .ZIP file as well. Please note that if the archive file includes different documents, the platform will offer you to certify each one independently – we advise you to do so, in order to find them more easily for the verification.

How long will the documents be certified ?

The documents will be certified forever on the Blockchain. The Blockchain being by essence impregnable, the ledger can’t be altered or erased.

What happens if you (Datatrust) disappear ?

The closure of the company wouldn’t compromise at all the evidence of certification. It is the whole purpose of Blockchain. As it is decentralised, it will be forever possible to establish the anteriority and integrity of the authentication.

For instance, anyone can trace all the transactions done on the Blockchain since its creation in 2015.

What Blockchain does Datatrust use ?

Our service is based on the Ethereum Blockchain, which best fits the authentication of documents. Ethereum network is much less congested than Bitcoin’s. For example, in July 2017, the mean transaction time was around one hour. Moreover, the governance issue regarding the evolution of the network is minor, and the continuity of the network is guaranteed (15.000 nodes).

How can I trace my transaction on the Blockchain ?

It is very easy to check the transaction, you only need to visit a website such as : https://etherscan.io/ and inserting the transaction number. You can find this number on your certificate, on the line “Anchor”.

What do the informations on the certificate mean ?

Type : The anchoring standard

Target Hash : The document footprint

Merkle Root : The tree root footprint

Anchor : The transaction number

These informations respect the Chainpoint V2 standard.

What happens if I misplace my document ?

Each certificate corresponds to a precise footprint, hence a specific document. If you forget or lose this document, you won’t be able to prove the authentication anymore. This is why it is imperative to keep it safe !

If you desire, Datatrust can store your documents. When certifying a file, you just need to click on “Upload your file to Datatrust”. The document will then be downloadable in the tab “Documents & certificates”. A data storage is available regarding your needs.

What happens if I misplace my certificate ?

You can find your certificate at any time on the platform, in the tab “Documents & certificates”. Click on “Download certificate” in the second column on the right.

Whatever happens, we always keep the certificates. Thus, you can always get the evidence of authentication, whenever you need it.

I have too many documents, how can I find the one I want ?

There is a quick and simple way to find any certified document. Click on the tab “Documents & certificates”, then click on “Filter” at the right of the screen. It will then be possible to filter the files according to their name, format, size, date…

What are the use cases ?

The Blockchain authentication offers boundless opportunities, whatever the business sector. Diploma, commercial register, design and template, insurance certificate, database, press release, business secrets, articles and work of art, administrative files…