Karen Azari hat Mathematik studiert und ihre Promotion am Institute of Science and Technology Austria (ISTA) unter der Betreuung von Krzysztof Pietrzak abgeschlossen. Anschließend wechselte sie an die ETH Zürich, wo sie wertvolle Lehrerfahrungen sammelte und von der Expertise von Dennis Hofheinz profitierte.
Innerhalb des Themenfeldes Kryptographie liegt ihr Fokus insbesondere auf der formalen Definition von Sicherheitsstandards und auf Sicherheitsbeweisen für kryptographische Protokolle. Sie beschäftigt sich unter anderem mit sicherem Gruppen-Messaging, Proof Systems für dezentrale Systeme sowie den Grundlagen ressourcenbeschränkter Kryptographie und ist stets offen dafür, neue Themenfelder innerhalb der Kryptographie zu erkunden.
It is great to have you on board as an Assistant Professor. We hope you have settled in well! How have the past few months been for you?
The last few months have been quite intense, but overall it was a great experience! After this first semester at University of Vienna, I feel that I fully arrived in my new position, including all its challenges regarding building up and interconnecting my new research group, setting up new courses, and applying for research grants. I am very happy for all the great support I got from my colleagues during this initial phase.
Your journey to computer science started with a degree in mathematics. How did the interest in computer science develop, and what is it that fascinates you about the field?
Having attended a high school with a linguistic focus, it did not even come to my mind to study computer science and also during my mathematics studies I got very little exposure to computer science. Despite their strong scientific relation, unfortunately, the faculties of mathematics and computer science are not very well connected and I wrote my MSc thesis in pure algebraic number theory, without any applications to computer science. For my PhD degree, however, I wanted to switch to more applied research and found the field of cryptography as a perfect fit. Cryptography lies well in the middle of computer science and mathematics, hence, allowed for a relatively smooth transition between fields.
While after high school I would never have seen myself in computer science – simply because I had a very wrong understanding of what this field really is about – for me this was a very good match and nowadays I am much more fascinated by general complexity-theoretic questions related to cryptographic primitives than by the concrete number theoretic problems on which these primitives are based. I really enjoy the close connection between computer science and discrete mathematics, which allows to analyze real-world computational problems through abstract thinking and logical reasoning.
I think it is a pity that especially girls often do not know about the beauty of computer science and therefore do not even consider the option of studying computer science after school, as was the case for me.
You also completed a master’s at the University of Music and Performing Arts Vienna. Do you feel that this (non-technical) degree helps you in computer science or provides a different perspective?
While these two studies are very different in character – one being based purely on logic, the other one being concerned with the expression of emotions – they both have in common that their studies require fully focused concentration and the tiniest detail – every single letter or note – makes a big difference. On the other hand, given that the focus is a different one, switching back and forth between these two disciplines allowed me to refresh my mind while staying focused, which often led to view things from a different perspective.
When did you first realize that you wanted to pursue an academic career? Was there a decisive moment?
When starting my studies, I did not intend to pursue an academic career and also later I could not point to a concrete decisive moment. I always enjoyed academic research a lot and I feel that devoting my professional life towards science and education is very rewarding. Also the international environment and the open discussions with my colleagues which I experience during research projects are very enriching and allow me to develop not only scientifically but also personally. My career approach was to always follow my interests, make my best efforts, and take the opportunities that open up. Overall this approach worked out very well for me.
Can you describe your current research in one sentence?
My research focuses on so-called “provable security” of cryptographic protocols (for example secure chat communication), where strong security properties of the protocol (for example privacy, integrity and authenticity of chat messages) can be guaranteed by a mathematical proof.
What has been your most challenging research project to date and why?
The biggest challenge was probably the first paper I got published. While I was lucky to be in a very supportive group with a healthy work culture, I was completely unsure where this journey would lead me and whether I would be able to significantly contribute. It was my first research experience, where I had a lot of discussions with a colleague on how to turn the intuition we had into a sound argument and whether this would be possible at all. Given the different background we had, it was sometimes hard to follow his completely different thoughts and perspective on the problem. While being challenging initially, this project was a very enriching experience and I learned to more clearly communicate to and learn from colleagues with diverse scientific background. In fact, I had a lot of fruitful collaboration with the same colleague with whom I worked on my first project, and once we came across the “language barrier”, our different strengths and perspectives complemented each other very well.
Looking ahead, what are your research plans for the coming years in Vienna?
For many widely used cryptographic protocols there is a big discrepancy between the security level that we require when employing the protocol in a wide range of applications, and the security level we can formally prove. Hence, we cannot fully exclude that a novel and devastating attack might be found and exploited in the future. My goal is to close this gap by proposing new technique for both the construction side as well as the proof side, aiming for practical protocols that achieve strong provable security guarantees.
An example for this discrepancy is adaptive security for communication in group chats: If we would know already at the start of the protocol execution which users would get corrupted at what time, we could provide efficient protocols that provide provable security whenever no member of the group is corrupted. While, intuitively, similar security guarantees should hold for those protocols if users get corrupted adaptively during protocol execution, proving this requires the study of novel proof techniques that we discovered only recently. In many similar scenarios, the problem of proving adaptive security is still completely open.
What was the most personally significant insight or realization you have gained so far during your time as a researcher?
To be persistent and optimistic. Some projects go perfectly smooth, with a well-defined problem, a clear outcome, and a specific technique to solve it. However, most research problems don’t follow this smooth pattern, but rather carry unforeseen challenges and often don’t lead to their intended goal, or at least not directly. Running into such an unforeseen barrier can be a quite negative experience for a fresh PhD student, being used to well-defined exercises that are known to be solvable within a given timeframe. But in fact, those challenges are what makes research so exciting. Instead of giving up once a difficulty arises, being persistent and exploring the problem from different angles most often leads to a better understanding and new insights.
When you think back to your time as a student, which courses did you enjoy the most? What is important to you in your current role as a teacher?
In my mathematics studies, I enjoyed most the courses related to discrete mathematics. In my music studies, I enjoyed music analysis a lot, where we explored the basic structure underlying a music piece. Had I studied computer science, which I honestly regret not to have seen as an option, my favorite topics would most likely have been complexity theory and algorithms. Generally, I enjoy to explore the abstract structure two seemingly different objects share.
I believe that the power of abstraction and logical thinking is extremely useful for every-day life, and for computer scientists of course even more. My goal as a teacher is therefore to derive new concepts interactively together with the students, so they understand the logics behind. This also allows to reduce the contents to be learned by heart to a minimum. I aim for a good working atmosphere, where students are challenged in a positive way, questions and mistakes are used to understand the details, and stress is reduced by communicating clear expectations.
For those just starting out: What advice would you give to today’s first-year students?
Take the start of your studies as a fresh start, independent of your school experience. Clearly differentiate between truly focused working time and recreational free time; a good and clear time management will help you to keep calm nerves also in stressful times. Take your time to fully understand logical concepts opposed to learning by heart, since otherwise the contents will be overwhelming and you will miss out on the beauty of computer science. Even if you don’t see right away where all these theoretical subjects should lead you, trust us lecturers that your efforts in early semester courses will pay off, not only in your further studies but also in real life as a programmer.
