Juan M. Estévez-Tapiador, John A. Clark, Julio César Hernández Castro. Non-linear Cryptanalysis Revisited: Heuristic Search for Approximations to S-Boxes. In Steven D. Galbraith, editor, Cryptography and Coding, 11th IMA International Conference, Cirencester, UK, December 18-20, 2007, Proceedings. Volume 4887 of Lecture Notes in Computer Science, pages 99-117, Springer, 2007. [doi]
Abstract is missing.