| Nicolas Tadeusz Courtois | |
| Birth Date: | 1971 11, mf=yes |
| Birth Place: | Lębork |
| Citizenship: | French |
| Field: | Computer science |
| Work Institutions: | University College London |
| Alma Mater: | University of Paris VI: Pierre et Marie Curie |
| Known For: | Cryptography, security |
Nicolas Tadeusz Courtois (born 14 November 1971) is a cryptographer. He was formerly senior lecturer in computer science at University College London.[1]
Courtois was one of the co-authors of both the XSL attack against block ciphers, such as the Advanced Encryption Standard,[2] [3] and the XL system for solving systems of algebraic equations[4] used in the attack. Other cryptographic results of Courtois include algebraic attacks on stream ciphers,[5] attacks on the KeeLoq and Hitag 2 systems used for remote keyless automobile entry systems,[6] and an analysis of cryptographic weaknesses in public transit smart cards including the London Underground Oyster card[7] and the Dutch OV-chipkaart.[6] [8] More recently, he has written about cryptocurrency.[9]
Courtois graduated from University of Paris VI: Pierre et Marie Curie, where he received his doctoral degree in cryptography.