Brigitte Vallée (born June 6, 1950, in Courbevoie, Hauts-de-Seine, France) is a French mathematician and computer scientist. She entered the École Normale Supérieure de Jeunes Filles in 1970, and received her PhD in 1986 at the University of Caen (Lattice reduction algorithms in small dimensions). She is Directrice de Recherche at the French CNRS at Université de Caen, since 2001 and specialized in computational number theory and analysis of algorithms. Amongst the algorithms she had studied are the celebrated LLL algorithm used for basis reductions in Euclidean lattice and the different Euclidean algorithms to determine GCD. The main tool used to achieve her results is the so-called dynamical analysis. Loosely speaking, it is a mix between analysis of algorithms and dynamical systems. Brigitte Vallée greatly contributed to develop this method.
In the early 90s, Brigitte Vallée’s work on small modular squares allowed her to hold the fastest factorisation algorithm with a proved probabilistic complexity bound. Nowadays, other factorisation algorithms are faster.