Cert4Trust is independent because we have developed our own blockchain infrastructure. Only trusted and pre-vetted partners are permitted to store hash values, whilst the verification of hash values is publicly accessible (‘Public Permissioned Blockchain’).

Our infrastructure is based on the source code of the Ethereum blockchain (www.ethereum.org) and utilises the ‘Proof-of-Authority’ consensus mechanism, whereby only authorised participants can approve the addition of a new block. Consequently, the consensus mechanism does not require an energy-intensive process, such as that used by Bitcoin (‘Proof-of-Work’), to secure the data.

As we also operate and secure the infrastructure ourselves, we have built up the necessary expertise through our collaboration. APIs (interfaces) and smart contracts (software modules used) are open-source components.

We use blockchain technology because it offers a number of advantages over a qualified signature when it comes to verifying electronic documents beyond any doubt.

We also record the status of each document (valid or invalid) in the blockchain. This allows a document that has already been issued to be subsequently declared invalid by the institution that created it. This is helpful, for example, if fraud is discovered retrospectively in an examination.
When the hash values are stored in the blockchain, a server-based timestamp is also recorded. This prevents documents from being signed retrospectively.
Signature solutions require a trusted authority to issue and verify digital signatures. In addition, software components are needed for signing and verifying the documents. Currently, signatures with a high or very high level of security require additional, separate hardware components. This makes implementation very complex.

A blockchain is a distributed database that enables information to be stored in a tamper-proof manner. Unlike traditional databases, information cannot be overwritten, but can only be added to. This ensures complete transparency regarding the information held at all times, even over time.

With blockchain, the hash values of digital documents are not stored on a central server but are distributed and kept up to date. On the one hand, this makes them more difficult for hackers to attack; on the other hand, it means that all node operators – rather than a single organisation – have control over the data.

Yes, the API for accessing the blockchain and the specification for the blockchain infrastructure are publicly available as open source under an MIT licence. If you are interested, please get in touch with us via our contact form.

1. Open the web application at check.cert4trust.de
2. Once you have accepted the terms of use, select the file you wish to check.
3. The browser calculates the hash value of the document.
4. Select ‘Check document’ and the application will display the result immediately.

If you have a digital certificate from one of our partners and would like to verify its authenticity, you can use Cert4Trust free of charge, 24/7.

You can find an overview of the organisations whose documents can be verified using Cert4Trust at https://check.cert4trust.de/partner.

Verifiable documents usually feature a notice regarding Cert4Trust printed on them.

Verified

The document you uploaded has been added to the Cert4Trust blockchain in its original form. This confirms that the document is unaltered and was indeed issued by this institution. The issuing institution is responsible for this information.

Revoked

The document you uploaded has been added to the Cert4Trust blockchain in its original form. This confirms that the document is unaltered and was indeed issued by this institution. The issuer has subsequently withdrawn the document. It is therefore no longer valid. The issuing institution is responsible for this information.

Not verified

The document you uploaded could not be verified. This does not necessarily mean that the document is not genuine. Rather, the ‘not verified’ result may be due to various reasons:
1) The file’s hash value is not stored in our blockchain.
2) The file’s hash value has been stored in our blockchain, but was identified as incorrect by the institution that issued the certificate and marked accordingly.
3) The document was accidentally altered, for example by opening it in Acrobat Reader and then saving it.

If you receive the status message ‘not verified’, please contact the issuing institution with any queries and note the following:

Only the original PDF documents issued by the institution can be verified. You should therefore only use the digital PDF document you received from your issuing institution. Scans of a paper certificate created at a later date cannot be verified.

As an HR professional, you can recognise the ‘original’ PDF document by a stamp or note such as ‘electronic copy’.

Yes this is possible. Please fill out our contact form to make an appointment.

If you are interested in using this service, please get in touch with us via our contact form.

As soon as you have met the necessary internal requirements for issuing and transmitting the digital documents, we will set up write access to our blockchain. You can then get started straight away.

No, it is not necessary to run your own node on our blockchain network in order to make your own certificates verifiable via the Cert4Trust blockchain.

And yes, as we have designed the infrastructure as a ‘public permissioned blockchain’, it is in principle possible for third parties to connect with their own node. The necessary specifications and start-up parameters are publicly available free of charge.

For onboarding – that is, setting up write access to our blockchain – we charge a one-off fee of €999.00.

In addition, a fee of €0.48 is charged for each write transaction (e.g. issuing a new document).

Document verification is free of charge.

No, verification is only possible using the original digital document provided by the issuer. Please contact the issuer to obtain or re-obtain the digital document. Check whether the institution that issued your certificate is a partner of the Cert4Trust system.

Cert4Trust processes only hash values and does not hold the documents or data at any time.

No personal data is stored on the blockchain, and we do not collect any personally identifiable data from you as part of the verification process.

The PDF document itself is processed locally on your computer or in the browser cache during verification and is not transmitted to Cert4Trust.

Your data cannot be viewed within the Cert4Trust system, as only encrypted hash values are processed. It is not possible to deduce the contents of the associated document or your identity from these values. The hash values stored on the blockchain can be viewed by anyone, in order to meet the requirement for maximum transparency of the system.

In the Cert4Trust system, it is not the documents themselves that are stored on the blockchain, but solely their hash values and information about the issuer, along with the issuer’s details regarding the validity of the relevant underlying document.