At a glance
To apply a qualified digital signature to a document, sproof sign allows you to choose from a wide range of certified trust service providers. This eID Hub is a unique interface that greatly simplifies the legally valid signing of contracts within the EU.
→ In the module “Signing with a National eID, ” you’ll learn how to identify yourself to a certified trust service provider.
Background and Key Terms
1. What is the eID Hub in sproof sign?
When you use sproof sign to apply a qualified digital signature to a document or invite others to sign it, you can select your preferred eID from a wide range of providers across Europe in our eID Hub. Thanks to this unique interface, you can easily handle contractual transactions and signature processes across national borders—in keeping with our motto: The signature that connects.
Example: You are sending a contract to individuals in different EU countries. You yourself have an ID-Austria identification. One of your contracting parties lives in Germany and is identified with D-Trust. Another contracting party is from Lithuania and is identified through Mobile ID. You want all contracting parties to provide a qualified signature. So, when preparing the signature invitation, you specify “QES” as the signature type for the document and invite your contracting parties. They can easily select their respective TSP from the eID Hub and use it to sign the document with a qualified and legally valid signature.
2. What is an eID?
In order to be able to use a qualified electronic signature (QES), a person must identify himself or herself with a qualified trust service provider (TSP). A qualified certificate is issued by a TSP, which is necessary for QES. This certificate is often referred to as an eID (“electronic identity”). A TSP provides trustworthy electronic signatures, seals or time stamps and is usually certified or monitored by a competent authority. In Austria, for example, this includes A-Trust GmbH. The European Union maintains a list of trusted lists of all member states (EUTL), which is accessible online.
Identification with a qualified trust service provider can be performed using various methods (e.g., video identification, app-based identification, German national ID card).
→ For detailed information on identification, see our article“QES Identification.”
→ If you’d like to learn more about types of electronic signatures, please refer to the“E-SignatureStandards” module.
List of Integrated Providers
We have already integrated the following certified trust service providers:
- Swisscom (Standard QES from sproof sign)
- Evrostrust
- German eID
- Smart ID
- Mobile ID
- Audkenni
- Autenticação ID Card
- Belgium ID Card
- Buypass
- CertEurope USB
- CertME
- certSIGN USB
- Czech ID Card
- Diia
- D Trust (Sign me)
- eParaksts eID
- Estonian ID Card
- Finnish ID Card
- Halcom
- Croatian ID Card
- ID-Austria
- InfoCert
- itsme
- Lithuanian ID Card
- primesign Mobile
- Simply Sign
- SPID Sign
- ZealID
Don’t see your preferred provider listed yet? Please contact us with your suggestion by email at contact@sproof.com.
Step-by-Step Instructions
The majority of the European population is already registered with one of the listed providers. If this is not the case, or if you would like an additional option, you can—provided you have a User+ license—register for the sproof Qualified Signature (provider: Swisscom).
→ More information about the identification procedure can be found in the module “QES Identification“.
To sign a document with a sproof sign in sproof Sign, follow these steps:
- Open a signature invitation or upload a document to sproof Sign yourself.
- Go to the “Sign Yourself” tab.
- Next to “Signature Type,” you can see which standard is currently selected (EES, FES, or QES).
- Click “Signature Type.” Select the signature type (Simple, Advanced, or Qualified). If you selected “Qualified,” you’ll find the eID Hub under “Additional QES Signature Providers (eID Hub),” which lists all currently available trust service providers.

- Click the search box to search for a specific provider.
- Click the drop-down menu to the right of the search field to filter by a specific country.
- Scroll through the list and select your preferred provider with a single click. In this example, ID-Austria (A-Trust) is used.
- If necessary, place signature fields and click the “Sign Now” button.
- The A-Trust login window opens as an overlay, and you can enter your login credentials.

10. Complete the signature using the second factor (usually the associated mobile app).

11. Done! sproof sign should now indicate that your document has been successfully signed with a qualified digital signature. You can now download the document, return to the dashboard, or close the overlay and stay in the editor.





