Dr. Nastja Cepak, UP FAMNIT

General

Nastja Cepak, a Slovenian cryptographer, is employed part-time as an assistant professor with a doctoral degree at University of Primorska Andrej Marušič Institute (UP IAM) and part-time at the CREAplus company in Ljubljana, which operates in the field of security technologies and cryptographic solutions in Slovenia.

The department within which Dr. Cepak works is responsible for the distribution of hardware security solutions. In addition, together with her colleagues, she works in consulting, system deployment, and system implementation support, while also providing customers with technical assistance. Because of this, they must have extensive knowledge of the products they work with.

Her colleagues are more specialized in networks and implementations, whereas she focuses on algorithms. In practice, this means that she is responsible for developing methods for protecting various types of data.

How did you decide to study mathematics, and why at University of Primorska Faculty of Mathematics, Natural Sciences and Information Technologies?

I completed all three levels of my studies at University of Primorska Faculty of Mathematics, Natural Sciences and Information Technologies. I studied Mathematics at both undergraduate and master’s level, and during my master’s studies I also simultaneously enrolled in the undergraduate programme in Computer Science. Although I did not complete that programme, I gained a great deal of additional and useful knowledge and skills from the field, which later proved extremely valuable in my career.

I continued my doctoral studies in the Mathematical Sciences programme and earned my PhD in cryptography, specifically in the area of symmetric cryptography and block ciphers.

I had been interested in natural sciences from an early age, but I made the final decision to study mathematics at the end of my second year of secondary school, when I realized that I was fascinated by patterns and by discovering how things can be defined and how structures can be manipulated.

At Gimnazija Koper, I had an outstanding mathematics teacher, Andrej Cuderman, who tragically died in a mountain accident during my final year. At that time, I approached another professor who taught advanced-level mathematics and was also an excellent educator, because I could not decide whether to study in Ljubljana or in Koper. I remember that she gave me a very encouraging comment, telling me not to worry and that studying at FAMNIT was an excellent choice. That gave me the extra confidence a secondary school student sometimes needs in order to make the next important step. That is how I came to study mathematics at FAMNIT. I was not immediately certain about pursuing a doctorate later on. Toward the end of my master’s studies, I was already working at CREAplus, where I am still employed today, and at that point I had to decide what to do next — continue working at the company, where a full-time position was already waiting for me, or continue studying.

At the same time, I realized that if I did not enroll in a doctoral programme at that point, I probably never would, because work eventually consumes your time and energy. I also knew that I wanted to earn a doctorate in a field that had always fascinated me and in which I wanted to continue working in the future, regardless of whether I stayed in academia or not.

That is why I chose cryptography. If that opportunity had not existed, I probably would not have enrolled in doctoral studies at all. Fortunately, it did exist, so cryptography became both my first and my final choice.

What do you enjoy most about working and researching in the field of cryptography?

I had already been interested in cryptography in secondary school, although when someone in secondary school says they are interested in cryptography, it usually means they have read The Da Vinci Code and become fascinated with puzzles.

So you begin studying mathematics and forget about cryptography for a while, but eventually all the fields somehow come together. One of the things I love about cryptography is that it creates a connection between pure mathematics, which I studied for so many years, and the security implications that affect the real world we live in.

How do we exchange information? How do we protect it? How do we authenticate ourselves? How can we use the internet safely? And what are the implications when states and military organizations control all this information — who can access it, and is it truly secure?

I see cryptography as a bridge between pure mathematics and what the world needs from the perspective of digital security.

What kind of future do you foresee for cryptography?

Cryptography will undoubtedly continue to play an increasingly important role in the future, but it cannot exist in isolation. I see this more and more clearly in practice.

Having stronger and more advanced cryptography with solid security proofs is the first prerequisite for protecting any other system. It is the essential first step — without it, we cannot really move forward. However, it is far from being the only requirement.

Every secure communication session begins with keys being exchanged and stored securely, and with encryption being performed in a secure environment.

And what are your plans for the future?

From both a teaching and research perspective, I hope to teach at least one cryptography course at UP FAMNIT next year. During the year when the pandemic began, I taught one semester experimentally for the first time, and I truly enjoyed it. I would very much like to repeat that experience in the coming academic year.

At the same time, I want to continue learning, because the field of security and cryptography is truly enormous. I would like to broaden my knowledge further and continue working in this field, which I personally find fascinating.

I especially appreciate the interaction and cooperation between academia and industry, and I often think about how knowledge from cryptography could be transferred even more effectively, particularly within the Slovenian environment. It is my wish that we succeed in connecting these areas even more closely.