1. Nicolas Courtois, La sécurité des primitives cryptographiques basées sur les problèmes algébriques multivariables MQ, IP, MinRank, et HFE, PhD Thesis, Paris 6 University, 2001, in French. Available at http://www.minrank.org/phd.pdf 268
2. Lect Notes Comput Sci;N. Courtois,2003
3. Magnus Daum, Patrick Felke, Some new aspects concerning the Analysis of HFE type Cryptosystems, Presented at Yet Another Conference on Cryptography (YACC’02), June 3–7, 2002, Porquerolles Island, France. 268
4. Magnus Daum, Das Kryptosystem HFE und quadratische Gleichungssysteme über endlichen Körpern, Diplomarbeit, Universität Dortmund, 2001. Available at http://emdaum@itsc.ruhr-uni-bochum.de
5. Jean-Charles Faugère, Report on a successful attack of HFE Challenge 1 with Gröbner bases algorithm F5/2, announcement that appeared in sci.crypt newsgroup on the internet on April 19th 2002.