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François Rodier 《Designs, Codes and Cryptography》2006,40(1):59-70
Boolean functions on the space
are not only important in the theory of error-correcting codes, but also in cryptography. In these two cases, the nonlinearity
of these functions is a main concept. Carlet, Olejár and Stanek gave an asymptotic lower bound for the nonlinearity of most
of them, and I gave an asymptotic upper bound which was strictly larger. In this article, I improve the bounds and get an
exact limit for the nonlinearity of most of Boolean functions. This article is inspired by a paper of G. Halász about the
related problem of real polynomials with random coefficients.
AMS Classification (2000) Primary: 11T71 · Secondary: 06E30 · 42A05 · 94C10 相似文献
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冀永强 《数学的实践与认识》2016,(1):275-279
对于正整数n,设Z(n)=min{m|m∈N,1/2m(m+1)≡0(modn)},称为n的伪Smarandache函数.设r是正整数.根据广义Ramanujan-Nagell方程的结果,运用初等数论方法证明了下列结果:i)1/2(-1+(8n+1)≤Z(n)≤2n-1.ii)当r≠1,2,3或5时,Z(2~r+1)≥1/2(-1+(2~(r+3)·5+41)).iii)当r≠1,2,3,4或12时,Z(2~r-1)≥1/2(-1+(2~(r+3)·3-23). 相似文献
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布尔“复合函数”的Walsh循环谱和自相关函数 总被引:1,自引:0,他引:1
本文利用布尔随机变量联合分布的分解式给出了布尔“复合函数”和某布尔函数符合率的分解算式,由此求得了布尔“复合函数”的 Walsh循环谱和自相关函数的计算公式,公式清楚地表明了“复合”所得布尔函数的 Walsh循环谱与起“复合”作用的函数和被“复合”的各函数所有线性组合的 Walsh循环谱之间的关系、“复合”所得布尔函数的自相关函数与起“复合”作用的函数谱和被“复合”的各函数的谱及相关函数之间的关系,这两个公式在布尔函数的密码学性质研究中会有广泛的应用. 相似文献
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We prove a stronger form of the conjectured Cusick-Cheon lower bound for the number of quadratic balanced Boolean functions. We also prove various asymptotic results involving B(k,m), the number of balanced Boolean functions of degree ≤k in m variables, in the case k=2. Finally, we connect our results for k=2 with the (still unproved) conjectures of Cusick-Cheon for the functions B(k,m) with k>2. 相似文献
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Propagation criteria and resiliency of vectorial Boolean functions are important
for cryptographic purpose (see [1–4, 7, 8, 10, 11, 16]). Kurosawa, Stoh [8] and Carlet [1]
gave a construction of Boolean functions satisfying PC(l) of order k from binary linear
or nonlinear codes. In this paper, the algebraic-geometric codes over GF(2m) are used to
modify the Carlet and Kurosawa-Satoh’s construction for giving vectorial resilient Boolean
functions satisfying PC(l) of order k criterion. This new construction is compared with
previously known results. 相似文献
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关于Wallis不等式的上界和下界 总被引:1,自引:0,他引:1
张国铭 《数学的实践与认识》2007,37(5):111-116
利用Wallis公式对两个已知的不等式进行了改进,相应地,我们得到了两个更加精细的结果. 相似文献
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The difficulty involved in characterizing the weight distribution of all Boolean functions of degree 3 is well-known [2, p. 446]. In [1] the author introduces a transformation on Boolean functions which changes their weights in a way that is easy to follow, and which, when iterated, reduces the degree of the function to 2 or 3. He concludes that it is just as difficult to characterize the weight of any function of degree 3 as it is for any other degree. The application of this transformation on a Boolean function defined on
, increases the number of its variables by two. On the other hand, in order to reduce the degree of a function to 2 or 3 it is necessary to apply the tranformation a number of times that grows exponentially with respect to m. In this paper, a factorization method on Boolean functions that allows the establishment of an upper bound for the number of applications of the transformation is presented. It shows that, in general, it is possible to significantly decrease the number of iterations in this process of degree reduction. 相似文献
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For a group G,we produce upper and lower bounds for the sum of the entries of the Brauer character table of G and the projective indecomposable character table of G.When G is a π-separable group,we show that the sum of the entries in the table of Isaacs' partial characters is a real number,and we obtain upper and lower bounds for this sum. 相似文献
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We introduce the notion of covering sequence of a Boolean function, related to the derivatives of the function. We give complete characterizations of balancedness, correlation immunity and resiliency of Boolean functions by means of their covering sequences. By considering particular covering sequences, we define subclasses of (correlation-immune) resilient functions. We derive upper bounds on their algebraic degrees and on their nonlinearities. We give constructions of resilient functions belonging to these classes. We show that they achieve the best known trade-off between order of resiliency, nonlinearity and algebraic degree. 相似文献
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Boolean functions possessing multiple cryptographic criteria play an important role in the design of symmetric cryptosystems. The following criteria for cryptographic Boolean functions are often considered: high nonlinearity, balancedness, strict avalanche criterion, and global avalanche characteristics. The trade-off among these criteria is a difficult problem and has attracted many researchers. In this paper, two construction methods are provided to obtain balanced Boolean functions with high nonlinearity. Besides, the constructed functions satisfy strict avalanche criterion and have good global avalanche characteristics property. The algebraic immunity of the constructed functions is also considered. 相似文献
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Upper and lower bounds are provided on the dimension of bivariate polynomial superspline spaces which are defined by enforcing
smoothness conditions across the interior edges of the underlying triangulation. The results generalize known bounds for classical
spline spaces. As an example of the usefulness of such bounds, we show how they can be applied to analyze a new macroelement. 相似文献
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Mass distribution principle is one of important tools in studying Hausdorff dimension and Hausdorff measure.In this paper we will give a numerical approximate method of upper bound and lower bound of mass distribution function f(x)(it is a monotone increasing fractal function)and its some applications. 相似文献
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We give an upper bound for the Stanley depth of the edge ideal of a complete k-partite hypergraph and as an application we give an upper bound for the Stanley depth of a monomial ideal in a polynomial ring S. We also give a lower and an upper bound for the cyclic module S/I associated to the complete k-partite hypergraph. 相似文献
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Minimization of a Quadratic Function of Many Variables Subject only to Lower and Upper Bounds 总被引:1,自引:0,他引:1
Methods for solving this problem are considered with particularreference to achieving maximum efficiency. A streamlined versionof Fletcher's (1971) method for quadratic programming is consideredand also a new approach based on the use of partial LDLT factorizations.Results on a wide variety of test problems indicate that theLDLT method is superior in both efficiency and error control.This method can often be expected to solve the problem in atime comparable to that required for a Choleski factorization,and always in a small multiple of this time. 相似文献
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