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A Boolean function with an even number n = 2k of variables is called bent if it is maximally nonlinear. We present here a new construction of bent functions. Boolean functions of the form f (x) = tr(α 1 x d1 + α 2 x d2), α 1 , α 2 , x ∈ F 2 n , are considered, where the exponents d i (i = 1, 2) are of Niho type, i.e. the restriction of x di on F 2 k is(More)
We exhibit an infinite class of almost perfect nonlinear quadratic polynomials from F 2 n to F 2 n (n ≥ 12, n divisible by 3 but not by 9). We prove that these functions are EA-inequivalent to any power function. In the forthcoming version of the present paper we will proof that these functions are CCZ-inequivalent to any Gold function and to any Kasami(More)
Quartz is a signature scheme based on an HFEv-trapdoor function published at Eurocrypt 1996. In this paper we study " inversion " attacks for Quartz, i.e. attacks that solve the system of multivariate equations used in Quartz. We do not cover some special attacks that forge signatures without inversion. We are interested in methods to invert the(More)
Recently a new class of collision attacks which was originally suggested by Hans Dobbertin has been introduced. These attacks use side channel analysis to detect internal collisions and are generally not restricted to a particular cryptographic algorithm. As an example, a collision attack against DES was proposed which combines internal collisions with side(More)
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