Previously, he was a PhD student at Orange Labs (former France Télécom R&D) and University of Versailles under the supervision of Henri Gilbert and Marc Girault. He also worked for two years at Ingenico as Cryptography Expert, and at Nanyang Technological University as Research Fellow. His main research interest is the design and the cryptanalysis of hash functions, and more generally symmetric cryptography primitives. He is one of the designers of ECHO (a SHA-3 submission candidate), PHOTON (a lightweight hash function) and LED (a lightweight block cipher).