Explained simply –
how Cert4Trust works

Documents such as certificates, authorisation notices and generally supporting evidences are required as proof for countless processes and procedures. For example, a job applicant’s school report is checked before recruitment, or proof of specialist knowledge is verified before authorisation is granted to practise a safety-critical profession. Forgeries are not always detectable – particularly in the case of digital documents – or can only be verified at great expense.

Using blockchain technology, Cert4Trust provides an automated, unequivocally validated assurance of the authenticity, origin and validity of digital documents.

01

Issue a digital document

The starting point is a digital document created in PDF/A format and made available to the holder (e.g. a training course graduate). This is done, for example, via the training provider’s digital portal.

As verification is only possible using this ‘original file’, it is important that the participant has access to this file. We therefore recommend that the document is also archived to enable it to be retrieved at a later date.

02

Generate the hash value for the document

To identify the document beyond any doubt, Cert4Trust uses what is known as a hash value – in other words, the document’s digital fingerprint. This value is a sequence of characters calculated on the basis of all the information contained in the document, and it changes as soon as any alteration is made to the document. If the hash value remains unchanged, it follows that neither the document nor its content can have been altered.

The hash value is calculated using the SHA3-256 algorithm when the document is created and can be recalculated at any time thereafter, provided the document is available.

Incidentally, it is not possible to deduce the content of the underlying document from the hash value.

03

Store the hash value in the blockchain

The hash value is stored in the Cert4Trust blockchain together with information regarding the document’s validity. This status can be changed at any time, for example if a document has been revoked. To this end, a so-called smart contract is used, which is issued on an individual basis for the relevant institution as part of the onboarding process.

No documents are transmitted to the Cert4Trust system; only the hash values are sent.

04

Check the document

The document can now be verified via the web application check.cert4trust.de. The application calculates the hash value for a document once it has been uploaded to the application. During the verification process, the blockchain is scanned and compared with the document’s hash value determined by the web application. If a digital document was not issued by a participating partner or has been subsequently altered, no matching hash value can be found.

Directly try out the validation of documents!

Download our Test-Dokument . Save it directly without opening the document.
Open the web application https://check.cert4trust.de
Accept the terms of use and upload the test document.
The application calculates the hash value and performs a security check.
When you select ‘Check document’, the application carries out a check against the values in our blockchain and displays the result immediately.

You can find advice and tips on how to use the service and what the test results mean in our FAQ.