Theoretical exercise became a revolutionary technique

When Ivan Bjerre Damgård first started getting interested in data encryption, everyone with any knowledge of the subject could gather in one room. Early in his research career, he developed a theory for the protection of data –  and now, 30 years later, practical applications are exploding. ​

By Sys Mehlsen Vestergaard, journalist, Aarhus University

When you ask Ivan Bjerre Damgård about his research, you are immediately struck by the enthusiasm he radiates. He has been active in his field for over 30 years, and his enjoyment of his research into cryptology and data security is undiminished.

“I still take a childlike satisfaction in getting a good idea and discovering that it works. In our world, we all live for those little ‘aha’ moments. When you’re waking up in the morning or just about to fall asleep and feel that ‘hey! – that’s how that works’,” explains this year's recipient of the Villum Kann Rasmussen Annual Award, 61-year-old Professor Ivan Bjerre Damgård from the Department of Computer Science at Aarhus University.

Damgård earned both his MSc and PhD at the same university. As a PhD student, he developed a theoretical description of what is now called multiparty computation – at the time a “purely theoretical exercise”, in Damgård’s words, but which has since evolved into a technique for ensuring the security of data users either want to keep to themselves or share with others without the risk of compromising confidentiality.

And the need for techniques to ensure precisely this kind of security has exploded with the digitisation of our society, which has also seen the multiplication of possible applications for multiparty computation.

When Damgård was first encouraged to pursue a research career by his former MSc project supervisor Professor Peter Landrock back in the mid-80s, he decided to set out on that path with an open mind.

“Peter advised me not to continue working on pure mathematics, which is what I did my Master’s thesis on, but to move into something more interdisciplinary, because that’s where it was possible to get funding. And so we started to get interested in coding theory and cryptology,” remembers Damgård.

“We found out that there was a course in Amesterdam at CWI (Centrum voor Wiskunde en Informatie, ed.) for PhD students in this field. Back then, it was possible to put everyone in cryptology in the same room – and I went down there – and I was sold.”

More to life

In light of the fact that Damgård then went on to became an important pioneer in the field here in Denmark and helped establish a completely new research programme at Aarhus University – a programme which is today one of the world’s best – it comes as a bit of a surprise to hear him describe his own career as shaped by coincidence –and not just in relation to his choice of research specialisation.

“Before my PhD, I wasn’t really sure what I wanted to do. After my MSc in mathematics and computer scientist, I did a subsidiary subject in music. You were allowed to do that back then. You were allowed to do lots of things back then,” he adds with a warm smile. After a moment, he adds:

“I thought that it would be nice to get a diploma proving what I could do.” And what Damgård could do – in addition to research – was play music. He had started playing quite a lot on a semiprofessional basis after attending a folk high school course in Askov after his first two years at university.

“I elected to take a classic winter course at Askov High School, one of our large traditional folk high schools. I didn’t want to wear blinkers. There had to be more to life – I was attracted by music and the history of ideas and all the other stuff. I always knew that I’d go back to my degree programme afterwards. It was just something I had to try.”

And he did return to Aarhus, to the university, to mathematics and computer science – with his own room in Residence Hall 9 in the University Park. In his free time, he played in a number of bands.

“It was great fun to do a subsidiary subject in music. That could have become my path, but then I spoke with Peter, and that was the direction I chose.”

I wouldn’t hesitate to call it...

Damgård continued to collaborate with the researchers he had met at CWI after his stay in Amsterdam, and his research project began to take shape. Before he had even completed his PhD, Damgård had laid the foundation for the subsequent decades of his research career – his theory of multiparty computation.

“I’ve been part of a fantastic story. I wouldn’t hesitate to call it a revolution. In the course of 30 years, we’ve gone from pure basic research to applied research. That’s a very slow rate of market penetration, you might say. There were some people who needed to understand that they had a need for data encryption and data protection.”

The banks were the first to demonstrate an interest in the technology.

“We need to remember that this was a technology from outer space when the banks came up with digital signatures. We were brought on as consultants because we could write code for that kind of thing. The technology was there before the need was there, broadly speaking. For example, someone had to figure out that some people might actually try to change the emails we send. No one had thought about that. Security hadn’t become absolutely crucial, as it is today.”

Good people ‘to play ball with’

In addition to his research, Damgård also founded a company, Cryptomathic, together with Peter Landrock and Jørgen Brandt, who are also researchers at Aarhus University. He has co-founded two additional companies since then, Partisia and Sepior. Although his expertise has become extremely sought-after in an increasingly digitised world, research has always been and remains Damgård’s true passion.

“At one point, I made a decision about where my primary focus was to be. I felt at home in research. I ended my engagement in Cryptomathic and took over teaching cryptology subjects. And things developed slowly but surely from then on. One grant followed another, and the group grew. We’ve had an easy time getting grants all along, we’ve been good – but have we also been lucky? Yes, we probably have, “ Damgård muses. Today, his research group has grown to include 30 researchers from 10 different countries.

Early career researchers come to Denmark to learn from him – Damgård is a living legend in their field.

He has published over 160 peer-reviewed scientific articles in the course of his career. He is the top-ranked scientist world-wide on the International Association for Cryptologic Research’s list of the most prolific authors in cryptography, and he has an H index of 59 on Google Scholar, according to his nomination for the Villum Kann Rasmussen Annual Award – an award which is given to “a researcher who has created research breakthroughs in the technical and natural sciences”. The award carries a cash prize of DKK 4.5 million earmarked for research as well as a personal cash prize of DKK 500,000 which goes to Damgård. Three years ago, Damgård also won a DKK 15 million ERC Advanced Grant. Such grants enable him to keep his research group functioning at a high level. 

“I have a fantastic group and good people to ‘play ball with’. And we are able to recruit exclusively on the basis of our good name and reputation,” Damgård says. 

Danish Music Award as folk composer of the year

Alongside his research career and business activities, Damgård is also pursuing a semi-professional career as a musician. He has been appointed an official ‘national folk musician’ by the Danish government, and he received a Danish Music Award as folk composer of the year in 2007, up against a  field of famous Danish musicians like Niels Skousen.

As Damgård puts it, “Music – you can’t live without it.” 

As the second great passion of his life, music is a good supplement to his research, he emphasises. And he is not the only person who feels like this, he has noticed:

“You need to think about something else. In fact, there are a lot of researchers who play music, and there’s a very clear connection between people who do something with maths or computer science on the one hand – and music on the other hand. There are so many of them that it can’t be a coincidence. Maybe it’s something to do with the patterns in music resonating with the brains of people who work with maths. A lot of people are under the mistaken impression that maths and computer science aren’t creative. In any case, that’s completely wrong,” says Damgård. And in any case – just for fun – instruments are sometimes brought to the department Christmas lunch for an impromptu jam session.

Even more music?

Music may even come to play an even more prominent role in his life. Damgård has not quite made up his mind about that. But in any case, not yet. He intends to carry on with his research projects full steam ahead, and when asked whether he expects his career to produce a second revolution, he replies:

"Well, in a sense, we’re still in the middle of one. The entire process of transmission from pure theory to the application of the theory is still going on. At first glance, I think it’s difficult to identify where a gigantic breakthrough could take place, but after all, you never know whether there’s something fantastic waiting right around the corner. There are lots of dead ends out there, mocking us. We break through some of them once in a while – the big ones, maybe every ten years or so. That’s not something you can plan.”