Yves-Alexandre de Montjoye, who was one of the winners of the 2015 Innovator Under 35 (Belgium) awards conferred by the MIT Technology Review, is working to bring big data and metadata under control in order to help preserve people’s privacy.

An innovator?

After earning a Bachelor’s degree in Engineering at the Catholic University of Leuven in Belgium, Yves-Alexandre de Montjoye threw himself into applied mathematics. At that time he didn’t look much like the stereotypical ‘mad mathematician’ but the great pioneering mathematicians Euler, Leibniz and Chasles were nevertheless his role models. Having completed his first MSc, he joined the first TIME (Top Industrial Managers for Europe) programme at the Ecole Centrale in Paris, a tertiary education institute specialising in engineering. His sojourn in France lasted two years and ‟this excellent training prepared me well for the research I am doing today,” he enthuses.

But it was in New Mexico, USA, at the Santa Fe Institute to be precise, that he carried out research into complex systems, which really inspired his intellect. ‟It gave me a taste for the type of research they do in the United States, which is more practical and closer to the actual issues of society.” It was this experience that motivated him to work for a Ph.D at the MIT Media Lab: ‟We’re working on the topic of  computational privacy. We draw inspiration from the elegance of actual physical models which we then combine with applied mathematics.”

The innovation?

Yves-Alexandre approaches the subject of computational privacy from two standpoints. Firstly he looks into the limits of data anonymisation when dealing with large quantities of data. We recently published a study on data from mobile phones, looking in particular how much information you need on a person in order to find him/her from among a large dataset.  We discovered that if you know four places where the person has been during the day with his/her mobile, you can uniquely identify that person in 95% of cases,” he reveals.

Secondly, he is trying to determine what can be inferred from metadata on individuals. ‟The theoretical question is what an algorithm can reveal about a person now and also in the future – when machine learning techniques will have evolved. Our experiment at MIT has shown that, for example, an algorithm could identify the test volunteers with reasonable accuracy.”

The flagship project of Yves-Alexandre and his team is at the meeting-point of these two areas. They have designed a platform called openPDS/SafeAnswers. First of all the platform (PDS stands for Personal Data Store) enables a user’s personal details to be stored in a secure space. Second, unlike traditional methods of data anonymisation, it has an interface which works on the basis of questions and answers, with user data linked to specific questions.

So what impact is this likely to have?

Yves-Alexandre basically wants to promote an ethical approach to the use of personal data: ‟We’re trying to ensure that the issues lurking behind the use of big data and metadata – data coming from credit cards, web browsing and mobile phones in particular – can be properly assessed.”

The openPDS/SafeAnswers project is designed to help people regain their right to privacy. ‟The idea is that researchers, for example, will use the platform to ask questions. These questions are sent to a third party which will provide access to that particular piece of information, limited to the subject of the question,” explains De Montjoye. He gives as an example a local authority that has closed road access to a bridge and wants to find out the impact this is having on local residents trying to get to work every day.

The openPDS/SafeAnswers system filters the information. ‟In our example, the town’s authorities don’t need to know what a given resident has been doing during the rest of the day. The principle is to restrict the information that a person makes available,” he points out, stressing: “We’re trying to find an efficient way of using data on people while still respecting their privacy.”

vie privée des citoyens

Helping people to regain control of their personal data: this is the aim of Yves-Alexandre’s research at the MIT Media Lab

And what does the future hold?

Everything still remains to be done to ensure that citizens’ data are afforded proper protection. Yves-Alexandre de Montjoye predicts that ‟there will be a lot of change on the company side  and on the regulatory side, following adoption of the new European Directive and in France as a result of action from CNIL [the French National Commission on Informatics and Liberty]. Meanwhile, he adds: “As far as I’m concerned, I intend to continue working along these lines, at the crossroads of ethics, technology and privacy policies. Ensuring that the right questions are asked regarding how people’s personal data are used, - that’s the essence of my work.”

The Belgian researcher also has strong views on the purpose of his research, underlining: ‟It’s important to me that my research should help to develop products, as well as raising people’s awareness of what metadata and big data are all about.”

By Pauline Canteneur