It is also according to him a citizen weapon

In the Office of Jacques Stern float a few discrete indices: the equations scribbled in red felt old whiteboard, a lone computer, a library that align with thick volumes on cryptology...

But his book "The Science of secrecy", on the art of encoding messages, is missing from the shelves. No trace, nor the range of decorations which crowns this former mathematician, as price Lazare Carnot, awarded in 2003 by the Academy of sciences, or the distinction envied for "Fellowship" in the prestigious International Association for Cryptologic Research, Jacques Stern is the only European to hold.

Nothing, in the setting of the Ecole normale supérieure, where he teaches, suggests that this slender man of fifty-seven years, black hair, sober gestures and raised voices, marked his mark the global scientific community. Nothing, if not his dark green eyes that suddenly lights when it refers to Cryptology: "A military weapon, breaking German codes, contributing to the Allied victory, details, with passion." A diplomatic weapon that, further to the interception of a telegram between the Germany and the Mexico, precipitated the United States in the first world war in 1917. "It is also, according to him, a citizen weapon. Are the exchange of confidential data not the pillars trade online, electronic voting, the personalized medical record or the 3 G phone "We are all constantly two cryptographic processors: a mobile phone and a credit card", continues Jacques Stern. Indeed, since 1998, its confidential report urged the French Government to democratize the cryptology.

At this "science of defence and the attack", which ensures algorithm in algorithm, to ensure "the integrity, authenticity and confidentiality of communications", Jacques Stern has spent twenty years of career and 150 scientific publications. "He is the father of modern French Cryptology," summarized David Naccache, Professor at the University of Paris-II, and was one of the 30 PhD Jacques Stern took under his wing. It is a monument. But he has never run after the honours.

"Always Excel."

Yet last week, he was awarded the highest national scientific distinction: it is the first computer scientist to receive the Gold Medal of the CNRS. "It is a grey eminence," said Arnold Migus, Director General of the CNRS. He still reviews this computer scientist, adolescent, receiving his first prize in mathematics in the general competition at the Sorbonne.

Jacques Stern chose early science, because "the lets you push the limits of the impossible". The only son of traders of Vanves was guided by a certainty: "I always wanted Excel in the field I chose". I didn't take the seconds ranks. "In 1968, he preferred the banks of the Ecole normale supérieure in the honours of Polytechnique. Despite his fiber of pedagogue, he did not hesitate to leave his position as young Professor of mathematics at the University of Caen, to turn to a secret discipline but concrete. "It has taken an extraordinary risk changing abruptly career." "At the time, it was a domain is just gone", says Arnold Migus.

Since then, Jacques Stern, father of two children and opera lover, was not busy. This pioneer, who leads the it Department of the Ecole normale supérieure, among others, gave momentum to the links, its computer lab, and has continued to develop mathematical models using computers to test.