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61.
Based on orthogonal Latin cubes, an image cryptosystem with confusion–diffusion–confusion cipher architecture has been proposed recently (Inf. Sci. 2019, 478, 1–14). However, we find that there are four fatal vulnerabilities in this image cryptosystem, which leave open doors for cryptanalysis. In this paper, we propose a reference-validation inference algorithm and design screening-based rules to efficiently break the image cryptosystem. Compared with an existing cryptanalysis algorithm, the proposed method requires fewer pairs of chosen plain-cipher images, and behaves stably since different keys, positions of chosen bits and contents of plain images will not affect the cryptanalysis performance. Experimental results show that our cryptanalysis algorithm only requires pairs of chosen plain-cipher images, where represents the image’s resolution. Comparative studies demonstrate effectiveness and superiority of the proposed cryptanalysis algorithm. 相似文献
62.
We introduce a linear method for constructing factor‐pair Latin squares of prime‐power order and we identify criteria for determining whether two factor‐pair Latin squares constructed using this linear method are orthogonal. Then we show that families of pairwise mutually orthogonal diagonal factor‐pair Latin squares exist in all prime‐power orders. 相似文献
63.
本文首次提出了 n维超立方体的层次结构模型 HHC,详细讨论了该结构中结点的分布及各结点的连接关系 .并利用 HHC,讨论了超立方体非对称比较模型的最优诊断算法 ,极大独立点集等问题 相似文献
64.
A sufficient condition is given for the multiparametric Hopf algebras to be Hopf* -algebras. Then a special subclass of the
-algebra related to a Latin square is given. After being completed, its generators are all of norm one. 相似文献
65.
Let FFv be the set of faulty nodes in an n-dimensional folded hypercube FQn with |FFv|≤n−2. In this paper, we show that if n≥3, then every edge of FQn−FFv lies on a fault-free cycle of every even length from 4 to 2n−2|FFv|, and if n≥2 and n is even, then every edge of FQn−FFv lies on a fault-free cycle of every odd length from n+1 to 2n−2|FFv|−1. 相似文献
66.
We show that for any positive integer k?4, if R is a (2k-1)×(2k-1) partial Latin square, then R is avoidable given that R contains an empty row, thus extending a theorem of Chetwynd and Rhodes. We also present the idea of avoidability in the setting of partial r-multi Latin squares, and give some partial fillings which are avoidable. In particular, we show that if R contains at most nr/2 symbols and if there is an n×n Latin square L such that δn of the symbols in L cover the filled cells in R where 0<δ<1, then R is avoidable provided r is large enough. 相似文献
67.
On the number of transversals in Cayley tables of cyclic groups 总被引:1,自引:0,他引:1
It is well known that if n is even, the addition table for the integers modulo n (which we denote by Bn) possesses no transversals. We show that if n is odd, then the number of transversals in Bn is at least exponential in n. Equivalently, for odd n, the number of diagonally cyclic latin squares of order n, the number of complete mappings or orthomorphisms of the cyclic group of order n, the number of magic juggling sequences of period n and the number of placements of n non-attacking semi-queens on an n×n toroidal chessboard are at least exponential in n. For all large n we show that there is a latin square of order n with at least (3.246)n transversals.We diagnose all possible sizes for the intersection of two transversals in Bn and use this result to complete the spectrum of possible sizes of homogeneous latin bitrades.We also briefly explore potential applications of our results in constructing random mutually orthogonal latin squares. 相似文献
68.
The Ryser Conjecture which states that there is a transversal of size in a Latin square of odd order is equivalent to finding a rainbow matching of size in a properly edge-colored using colors when is odd. Let be the minimum degree of a graph. Wang proposed a more general question to find a function such that every properly edge-colored graph of order contains a rainbow matching of size , which currently has the best bound of by Lo. Babu, Chandran and Vaidyanathan investigated Wang’s question under a stronger color condition. A strongly edge-colored graph is a properly edge-colored graph in which every monochromatic subgraph is an induced matching. Wang, Yan and Yu proved that every strongly edge-colored graph of order at least has a rainbow matching of size . In this note, we extend this result to graphs of order at least . 相似文献
69.
In this paper we investigate light dual multinets labeled by a finite group in the projective plane defined over a field . We present two classes of new examples. Moreover, under some conditions on the characteristic of , we classify group-labeled light dual multinets with lines of length at least 9. 相似文献
70.
We prove that, with the single exception of the 2‐group C, the Cayley table of each Abelian group appears in a face 2‐colorable triangular embedding of a complete regular tripartite graph in an orientable surface. © 2009 Wiley Periodicals, Inc. J Combin Designs 18: 71–83, 2010 相似文献