A non-alternate 3D structure and its practical security evaluation against differential and linear cryptanalysis

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Qian Wang ◽  
Chenhui Jin
Keyword(s):  
3D Structure ◽  
Security Evaluation ◽  
Linear Cryptanalysis ◽  
Practical Security

scholarly journals Security evaluation on Simeck against zero-correlation linear cryptanalysis

2018 ◽  
Vol 12 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Kai Zhang ◽  
Jie Guan ◽  
Bin Hu ◽  
Dongdai Lin
Keyword(s):  
Security Evaluation ◽  
Linear Cryptanalysis ◽  
Zero Correlation

Practical Security against Differential and Linear Cryptanalysis for SMS4-like Cipher

2013 ◽  
Vol 8 (8) ◽  
Author(s):  
Qiu-Yan Wang ◽  
Bin Zhang ◽  
Chen-Hui Jin
Keyword(s):  
Linear Cryptanalysis ◽  
Practical Security

scholarly journals A Strategy for Constructing Fast Round Functions with Practical Security Against Differential and Linear Cryptanalysis

1999 ◽  
pp. 264-279 ◽  
Author(s):  
Masayuki Kanda ◽  
Youichi Takashima ◽  
Tsutomu Matsumoto ◽  
Kazumaro Aoki ◽  
Kazuo Ohta
Keyword(s):  
Linear Cryptanalysis ◽  
Practical Security

scholarly journals Improving the MILP-based Security Evaluation Algorithm against Differential/Linear Cryptanalysis Using A Divide-and-Conquer Approach

2020 ◽  
pp. 438-469
Author(s):  
Chunning Zhou ◽  
Wentao Zhang ◽  
Tianyou Ding ◽  
Zejun Xiang
Keyword(s):  
Search Algorithm ◽  
Optimal Solution ◽  
Divide And Conquer ◽  
Mixed Integer ◽  
Feasible Region ◽  
Security Evaluation ◽  
Linear Cryptanalysis ◽  
Minimum Number ◽  
Evaluation Algorithm ◽  
Symmetric Key

In recent years, Mixed Integer Linear Programming (MILP) has been widely used in cryptanalysis of symmetric-key primitives. For differential and linear cryptanalysis, MILP can be used to solve two kinds of problems: calculation of the minimum number of differentially/linearly active S-boxes, and search for the best differential/linear characteristics. There are already numerous papers published in this area. However, the efficiency is not satisfactory enough for many symmetric-key primitives. In this paper, we greatly improve the efficiency of the MILP-based search algorithm for both problems. Each of the two problems for an r-round cipher can be converted to an MILP model whose feasible region is the set of all possible r-round differential/linear characteristics. Generally, high-probability differential/linear characteristics are likely to have a low number of active S-boxes at a certain round. Inspired by the idea of a divide-and-conquer approach, we divide the set of all possible differential/linear characteristics into several smaller subsets, then separately search them. That is to say, the search of the whole set is split into easier searches of smaller subsets, and optimal solutions within the smaller subsets are combined to give the optimal solution within the whole set. In addition, we use several techniques to further improve the efficiency of the search algorithm. As applications, we apply our search algorithm to five lightweight block ciphers: PRESENT, GIFT-64, RECTANGLE, LBLOCK and TWINE. For each cipher, we obtain better results than the best-known ones obtained from the MILP method. For the minimum number of differentially/linearly active S-boxes, we reach 31/31, 16/15, 16/16, 20/20 and 20/20 rounds for the five ciphers respectively. For the best differential/linear characteristics, we reach 18/18, 15/13, 15/14, 16/15 and 15/16 rounds for the five ciphers respectively.

The low-resolution 3D-structure of porin, a channel-forming protein in E. coliouter membranes

1983 ◽  
Vol 41 ◽  
pp. 440-441
Author(s):  
A. Engel ◽  
D.L. Dorset ◽  
A. Massalski ◽  
J.P. Rosenbusch
Keyword(s):  
Crystal Packing ◽  
3D Structure ◽  
Gram Negative Bacteria ◽  
Protein Ratio ◽  
Crystal Forms ◽  
Large Molecules ◽  
Functional Studies ◽  
Voltage Dependent ◽  
Planar Membranes ◽  
Hexagonal Arrays

Porins represent a group of channel forming proteins that facilitate diffusion of small solutes across the outer membrane of Gram-negative bacteria, while excluding large molecules (>650 Da). Planar membranes reconstituted from purified matrix porin (OmpF protein) trimers and phospholipids have allowed quantitative functional studies of the voltage-dependent channels and revealed concerted activation of triplets. Under the same reconstitution conditions but using high protein concentrations porin aggregated to 2D lattices suitable for electron microscopy and image processing. Depending on the lipid-to- protein ratio three different crystal packing arrangements were observed: a large (a = 93 Å) and a small (a = 79 Å) hexagonal and a rectangular (a = 79 Å b = 139 Å) form with p3 symmetry for the hexagonal arrays. In all crystal forms distinct stain filled triplet indentations could be seen and were found to be morphologically identical within a resolution of (22 Å). It is tempting to correlate stain triplets with triple channels, but the proof of this hypothesis requires an analysis of the structure in 3 dimensions.

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