Cryptography whizz Anne Canteaut awarded Irène-Joliot Curie prize

Life is full of surprises... After doing science for my classe préparatoire* in Lille, I didn’t know what field to choose but I was certain of one thing: it wasn't going to be IT.

I ruled out engineering schools where the emphasis was on computer science and decided on ENSTA Paris, which I felt was more geared towards mathematics. It was there that I really discovered what computer science, programming and algorithms are all about.

Then, during a class at ENSTA I discovered cryptography, a field at the intersection of mathematics and computer science. This appealed to me and so I went to see the professor, who put me in touch with two people, one of whom was Paul Camion, who was working at the Inria research centre in Rocquencourt at the time. I reached out to him and he agreed to be my PhD supervisor.

* In France classes préparatoires are an intensive two-year post-baccalauréat course designed to prepare the best students for entry into the Grandes Écoles.

I’m a member of  COSMIQ an Inria project team made up of eight permanent researchers that is focused on designing and analysing the security of cryptographic algorithms in both a classical and a quantum setting. My own personal research interest is cryptographic primitives. Designed to carry out tasks with high levels of accuracy and without making any errors, these are the building blocks on which security protocols or systems (such as electronic voting protocols) are based.

I’m particularly interested in symmetric cryptographic primitives (also known as secret-key primitives). These primitives are symmetric because a secret is shared between the protagonists: the key allowing a message to be encrypted or decrypted. My job is to create high-performance, secure primitives, in addition to testing and assessing the safety of existing primitives - what is known as cryptanalysis.

We choose a system and then try to break it. The method is similar in some ways to what you read about in crime fiction: it’s all about gathering clues, before then examining the pieces scattered on the floor in front of you and trying to put them into some order, pulling at threads until you identify a possible flaw. 

Working collaboratively is very important. It’s really beneficial to be surrounded by people with different qualifications and different ways of thinking. As I often say, it wasn’t just thanks to Turing and cryptanalysts that the Allies were able to break the Enigma cipher machine used by the Nazis during the Second World War. It took a group made up of linguists, cryptanalysts, crossword enthusiasts, mathematicians and chess players to crack the code.
 

There are three main changes which cryptographic algorithms have to be able to keep pace with. The first regards the growing diversity of platforms on which they are used: as well as computers or microchips, they are also now used on things like car keys and public transport passes. Increasingly minimalist, stripped back systems have to be designed for such restrictive environments. 

The second change relates to the variety of ways in which they are used. For a long time cryptography was mainly used to ensure the confidentiality of communications or to protect the integrity of data. We are now working on primitives and systems which could help us prove that an algorithm has made the right calculations based on a dataset which cannot be made public, such as when dealing with health data, for example. The third and final change is linked to the need to create cryptographic algorithms capable of withstanding quantum computers.
 

It was a real honour to receive this award. Of course, it would be good if there were no distinction between female and male researchers. But it's still relevant given that only 19% of Inria researchers are women. We have to show future generations, particularly girls, that they can have a career in science.

Since being awarded this prize, I’ve taken on a sort of ambassadorial role: I've been regularly invited to give talks on science and IT to students at schools and universities, as well as to the general public. I reach out to everyone, girls and boys alike, trying to show them that computer science is very different from the stereotypes often associated with it. There are a lot of major disciplinary fields within it.
 

I’ve been a supervisor to many PhD students and I’m always telling them to do what makes them happy. Research is a difficult, intellectually demanding activity, and so it’s essential that you can derive satisfaction from working on a subject. You also need curiosity and perseverance. In my field, for example, you can’t break a cryptographic algorithm in a day. And sometimes it won't be possible at all, even after spending months on it. But that comes with the territory of being a researcher.

It’s often a topic for discussion in the public sphere. There’s even talk in the USA of “cryptowars.” Some political groups have floated the idea of banning cryptography. It's true that it can be used by people with bad intentions, such as members of terrorist groups sending encrypted messages to one another. But with each discussion it becomes clear that there are more advantages to using cryptography than to banning it, supposing that's even possible - encryption algorithms are public and will most likely continue to be used. 

We should look for inspiration to pharmacovigilance, which has an established procedure for ruling on such issues: drawing on scientific research, a commission examines the positive effects and side effects of medicinal products before deciding whether or not to issue marketing authorisation, sometimes re-evaluating its decision. It’s a shame that a similar system isn’t in place for digital technology that would make it possible to assess both the benefits and the potential risks.

 

• 1996: PhD in computer science from Sorbonne University (formerly Paris 6). Thesis on “Attacks on low-weight cryptosystems and construction of t-resilient functions” (PDF).
• 1997 - 1998: postdoc at ETH Zurich.
• 1998 - 2006: Inria researcher at the Rocquencourt centre.
• 2006: Inria director of research.
• 2007 - 2019: scientific head of the Inria project team Secret (cryptographic algorithms).
• 2017-2019: head of science at the Inria Paris centre.
• 2019: honorary doctorate from the University of Bergen (Norway).
• 2019 - 2023: chair of the Inria Evaluation Committee.
• Since 2019: director of research within the Inria project team COSMIQ (symmetric cryptography, code-based cryptography and quantum information).
• 2024: elevated to the rank of IACR Fellow 2024 “for influential contributions to symmetric cryptography and Boolean functions, and for exemplary service to the symmetric cryptography community.”
   

The Irène Joliot-Curie prize in brief

Launched in 2001, the Irène Joliot-Curie prize is awarded by the French Ministry of Higher Education and Research, with support from the French Academy of Sciences and the French Academy of Technology. The aim of this award, named after the daughter of physicists Marie and Pierre Curie, who won the Nobel Prize for Chemistry in 1935 alongside her husband, is to recognise the contribution made by women to research and technology in France, shining a spotlight on female scientists who are leading standout careers.

Two Inria researchers received awards this year. Alongside Anne Canteaut, Virginie Galland Ehrlacher, member of the Inria project team Matherials, was awarded the “Young Female Scientist” award for her work aimed at creating new digital models for solving large-scale problems.

Find out more

• Six leading female researchers earn Irène Joliot-Curie awards, French Ministry of Higher Education and Research, (in French), 07/03/2024.
• Anne Canteaut, cryptography trailblazer, ENSTA Paris, 20/12/2023.
• Profile of Anne Canteaut, winner of the 2023 Irène Joliot-Curie prize, French Ministry of Higher Education and Research, (in French), 01/03/2024.
• Is impenetrable writing a possibility? lecture by Anne Canteaut (video, in French), Collège de France, 21/10/2022.