17. December 2021, School, University, vocational education and training

Secure and digital signing with sproof

Whether contracts, certificates or delivery bills – countless documents are waiting to be verified, certified or signed every day. Not only to save paper, but also to make these important processes faster and, above all, more secure, entrepreneurs Clemens Brunner, Fabian Knirsch and Erich Höpoldseder founded the Salzburg-based startup sproof in 2019. Their application “sproof sign” is currently used, for example, to digitally sign annual reports from schools, exam results, certificates and complete degrees from universities.

The tool is particularly popular for distance learning students, who can use it to obtain the final document without much hassle. Other use cases can also be found in university administration – for example, to conclude contracts with partner organizations. In addition, sproof is used to digitize and digitally sign work, internship or vocational training certificates from institutes and organizations. This contributes to sustainability and brings security to the transmission of digital documents.

Digital and legally compliant

The cloud-based application couldn’t be simpler: Upload a document, sign it, assign a signature, and send it on as needed. And that’s exactly what makes the FH Salzburg spin-off so successful. At present, it is not only growing fast, but is also developing rapidly. The message is still clear – “sproof is Europe’s most secure digital signature,” says CEO and programmer Clemens Brunner. Indeed, the application meets all the prescribed requirements for legally binding digital signatures according to the current eIDAS regulation. In general, the following also applies: “Qualified digital signatures are legally equivalent to handwritten signatures. What’s more, the services are hosted via European servers, so the offerings are all also DSGVO-compliant.


With sproof, documents can be signed easily and legally valid digitally. (photo: Sproof)

Not just a simple signature

Regardless of whether internal or external documents need to be signed: with “sproof sign”, neither pen nor paper is required. The desired document is placed in the dashboard of the web application – either by having it already available digitally, by photographing it or by scanning it – and then edited. Users can sign directly with the mouse on the screen, by uploading a photo of their handwriting or with a qualified signature (e.g., a cell phone signature). The qualified digital signature also requires a one-time identification with an ID card – this makes it legally valid.

For private use, sproof is free of charge. Premium rates for corporate customers include a number of additional features, such as the ability to sign multiple documents simultaneously. In addition, users of these offers can also create templates, integrate the tool into the in-house IT system, or edit and manage the documents.

Forgery-proof bit by bit

Although the process with sproof sign only takes a few minutes, it is also more forgery-proof than a simple scan. “Especially now that anyone can actually edit documents with a cell phone or simple image editing software, this is an important point,” says Clemens. This is because the document is also signed “in the background” every time it is signed with sproof. This verifies the entire document, every single bit. “If someone were to change it afterwards, it would be recognizable, the signature would no longer fit. Digital signatures are also automatically verified by our software, so there’s no need for analog appraisal.”

Documents can also be digitally signed by multiple people. (photo: sproof)

Conquering the market with a larger team

They worked on an important further development of their product during the Covid pandemic in 2020: since then, individuals have also been able to issue qualified digital signatures. Before that, this was only possible for organizations and companies. As a result, despite the global crisis, the startup’s field of application has expanded, attracting new customers such as Sony DADC and the federal accounting agency.

An investment is now expected to help grow the team as well. “We want to grow so we can establish sproof even more in the European market.” In September 2021, however, they still moved regionally – to a new office in the Wissenspark, not far from the FH Salzburg, from which they sprang two years ago. Perhaps also to keep an eye out for new talent at their renowned former university …

The founders of sproof: Erich Höpoldseder, Clemens Brunner und Fabian Knirsch. Credit: Sandra Lagler/sproof GmbH

We asked Clemens Brunner

Congratulations on your new investors! What was important to you?

In any case, we didn’t want “just” financing, but smart money. In other words, investors who are also involved, who support us with know-how. Fortunately we found that! We are really happy about our investors, Berthold Baurek Karlic, President of the European Super Angels Club and founder of Venionaire Capital, and the business angel Michael Repnik, with whom we have a partnership relationship where we can discuss things.

What do you want to invest the “high six-figure sum” of the investment round in the fall of 2021 primarily in?

Definitely in our employees and our growth. So the funding will mainly go towards human ressources. We want to build up a strong team. Of course, we want to strengthen our software development work, but we also want to expand areas such as marketing and sales. These are the three points of view that we definitely want to keep in mind in all our future plans. The goal is a homogeneous team that can cover all areas.

That means the plan is to market sproof even more internationally?

Yes, absolutely. Our goal is to cover all of Europe broadly. We don’t just want to be successful in Austria, that was clear from the start. The legal situation regarding electronic signatures does not only apply to the domestic market. These are European laws, so with sproof sign we can offer all European companies legally valid digital signatures.


Eve hat sich nach der Kommunikationsarbeit in der Salzburger Innovationsszene als Texterin in Wien selbstständig gemacht. Der Funke ist über die Distanz aber nicht erloschen: Nach wie vor schreibt sie am liebsten über innovative Unternehmer:innen und ihre spannenden Ideen. Dafür geht ihr im EdTech Bereich sicherlich nicht so schnell der Stoff aus.

More articles

The following articles might also interest you.

Photo: Innovation Salzburg/Andrea Kurz

Keep calm and keep learning: The EdTech Future Journey 2024

23. April 2024

Read article
Foto: Innovation Salzburg/Benedikt Schemmer

This is the EdTech Austria team: Project Leader Jools Turrell

15. February 2024

Read article
Photo: Sincerely Media on Unsplash

ISTE Seal: The Seal of Approval for Digital Learning Tools

20. December 2023

Read article
Foto: Evelyn Baier-Schmid

Programming made easy: Coding Day 2023

27. November 2023

Read article
Photo: Sebastian Pandelache on Unsplash

Early Childhood Education Part 2: The Course is set on the Parents’ Screen

20. November 2023

Read article