A CNRS Silver Medal for Jean Goubault-Larrecq
Jean-Goubault Larrecq - © INRIA / Photo J.-M. Ramès
Jean Goubault-Larrecq, leader of the Secsi project team, has just been awarded a CNRS 2011 Silver Medal, for the INS2I (Institute for Information Sciences and Technologies).
The CNRS Silver Medal distinguishes a researcher for the originality, quality and importance of his work, which is recognised both nationally and internationally.
Jean Goubault-Larrecq's first research work concerned automatic theorem proving, specification and formal proving of software and the semantics of programming languages.
In particular, he was among the first, in 1994, to show that BDDs (binary decision diagrams), which were increasingly popular in circuit verification, could also serve as the basis of an effective first-order logical theorem prover. He worked as a research engineer at Bull S.A. until 1996 and then was a guest researcher for six months at Karlsruhe University, where he proposed, with Prof. Peter H. Schmitt, a new proof search algorithm for linear time temporal logic.
Once he returned to France he joined a technology transfer joint venture between Bull S.A. and Inria, GIE Dyade, where he worked on the security of cryptographic protocols.
In 2000 he became a professor at ENS Cachan where he launched a new research activity in computer security, with Hubert Comon-Lundh, in particular. This began to take shape with the creation of the Secsi project team in 2002 (security of information systems), of which he is the scientific head.
Secsi was a success, a highly talented team, and is widely recognized on the international scene. As for Jean Goubault-Larrecq, he has focused on intrusion detection and creating, with Julien Olivain, the Orchids
software programme. This software still has unique detection capacities based on complex correlations between system or network events.
He has also taken techniques in proving encryption protocols in new directions: integrating equational theories, static analysis of C code using cryptographic primitives to ensure confidentiality or automated generation of formal security proofs (and not just a simple yes/no answer).
A confluence of needs then led him to try and understand how to model the semantics of languages or systems that operate not only according to non-deterministic choices but also probabilistic ones. As a result he proposed two satisfactory models in 2007, one based on a review of the notion of capacity, according to Choquet, and another based on a notion that Walley, in financial mathematics, calls previsions. The two are forms of "non-additive probabilities". He developed a large share of the theory, through a domain theory approach, and more generally, from a topological perspective. It was this research work that ensured his international reputation today.