scholarly journals Comparing Large-unit and Bitwise Linear Approximations of SNOW 2.0 and SNOW 3G and Related Attacks

2021 ◽  
pp. 71-103
Author(s):  
Xinxin Gong ◽  
Bin Zhang
Keyword(s):  
Linear Approximation ◽  
The Other ◽  
Initial State ◽  
Large Unit ◽  
Research Results ◽  
Linear Approximations ◽  
Correlation Attack ◽  
Correlation Attacks

In this paper, we study and compare the byte-wise and bitwise linear approximations of SNOW 2.0 and SNOW 3G, and present a fast correlation attack on SNOW 3G by using our newly found bitwise linear approximations. On one side, we reconsider the relation between the large-unit linear approximation and the smallerunit/ bitwise ones derived from the large-unit one, showing that approximations on large-unit alphabets have advantages over all the smaller-unit/bitwise ones in linear attacks. But then on the other side, by comparing the byte-wise and bitwise linear approximations of SNOW 2.0 and SNOW 3G respectively, we have found many concrete examples of 8-bit linear approximations whose certain 1-dimensional/bitwise linear approximations have almost the same SEI (Squared Euclidean Imbalance) as that of the original 8-bit ones. That is, each of these byte-wise linear approximations is dominated by a single bitwise approximation, and thus the whole SEI is not essentially larger than the SEI of the dominating single bitwise approximation. Since correlation attacks can be more efficiently implemented using bitwise approximations rather than large-unit approximations, improvements over the large-unit linear approximation attacks are possible for SNOW 2.0 and SNOW 3G. For SNOW 3G, we make a careful search of the bitwise masks for the linear approximations of the FSM and obtain many mask tuples which yield high correlations. By using these bitwise linear approximations, we mount a fast correlation attack to recover the initial state of the LFSR with the time/memory/data/pre-computation complexities all upper bounded by 2174.16, improving slightly the previous best one which used an 8-bit (vectorized) linear approximation in a correlation attack with all the complexities upper bounded by 2176.56. Though not a significant improvement, our research results illustrate that we have an opportunity to achieve improvement over the large-unit attacks by using bitwise linear approximations in a linear approximation attack, and provide a newinsight on the relation between large-unit and bitwise linear approximations.

scholarly journals Resistance of SNOW-V against Fast Correlation Attacks

2021 ◽  
pp. 378-410
Author(s):  
Xinxin Gong ◽  
Bin Zhang
Keyword(s):  
Linear Approximation ◽  
Mobile Communication ◽  
Time Complexity ◽  
Stream Ciphers ◽  
Design Document ◽  
Linear Approximations ◽  
Correlation Attack ◽  
Correlation Attacks ◽  
Memory Complexity ◽  
Fast Correlation Attacks

SNOW-V is a new member in the SNOW family of stream ciphers, hoping to be competitive in the 5G mobile communication system. In this paper, we study the resistance of SNOW-V against bitwise fast correlation attacks by constructing bitwise linear approximations. First, we propose and summarize some efficient algorithms using the slice-like techniques to compute the bitwise linear approximations of certain types of composition functions composed of basic operations like ⊞, ⊕, Permutation, and S-box, which have been widely used in word-oriented stream ciphers such as SNOW-like ciphers. Then, using these algorithms, we find a number of stronger linear approximations for the FSM of the two variants of SNOW-V given in the design document, i.e., SNOW-V σ0 and SNOW-V⊞8, ⊞8. For SNOW-V σ0, where there is no byte-wise permutation, we find some bitwise linear approximations of the FSM with the SEI (Squared Euclidean Imbalance) around 2−37.34 and mount a bitwise fast correlation attack with the time complexity 2251.93 and memory complexity 2244, given 2103.83 keystream outputs, which improves greatly the results in the design document. For SNOW-V⊞8, ⊞8, where both of the two 32-bit adders in the FSM are replaced by 8-bit adders, we find our best bitwise linear approximations of the FSM with the SEI 2−174.14, while the best byte-wise linear approximation in the design document of SNOW-V has the SEI 2−214.80. Finally, we study the security of a closer variant of SNOW-V, denoted by SNOW-V⊞32, ⊞8, where only the 32-bit adder used for updating the first register is replaced by the 8-bit adder, while everything else remains identical. For SNOW-V⊞32, ⊞8, we derive many mask tuples yielding the bitwise linear approximations of the FSM with the SEI larger than 2−184. Using these linear approximations, we mount a fast correlation attack with the time complexity 2377.01 and a memory complexity 2363, given 2253.73 keystream outputs. Note that neither of our attack threatens the security of SNOW-V. We hope our research could further help in understanding bitwise linear approximation attacks and also the structure of SNOW-like stream ciphers.

scholarly journals Generating Graphs Packed with Paths Estimation of Linear Approximations and Differentials

2018 ◽  
pp. 265-289
Author(s):  
Mathias Hall-Andersen ◽  
Philip S. Vejre
Keyword(s):  
Linear Approximation ◽  
The Other ◽  
Differential Cryptanalysis ◽  
Linear Approximations ◽  
Correlation Distribution ◽  
Optimal Linear ◽  
Symmetric Key ◽  
Differential Attacks ◽  
Linear Correlations ◽  
Dependent Correlation

When designing a new symmetric-key primitive, the designer must show resistance to known attacks. Perhaps most prominent amongst these are linear and differential cryptanalysis. However, it is notoriously difficult to accurately demonstrate e.g. a block cipher’s resistance to these attacks, and thus most designers resort to deriving bounds on the linear correlations and differential probabilities of their design. On the other side of the spectrum, the cryptanalyst is interested in accurately assessing the strength of a linear or differential attack.While several tools have been developed to search for optimal linear and differential trails, e.g. MILP and SAT based methods, only few approaches specifically try to find as many trails of a single approximation or differential as possible. This can result in an overestimate of a cipher’s resistance to linear and differential attacks, as was for example the case for PRESENT.In this work, we present a new algorithm for linear and differential trail search. The algorithm represents the problem of estimating approximations and differentials as the problem of finding many long paths through a multistage graph. We demonstrate that this approach allows us to find a very large number of good trails for each approximation or differential. Moreover, we show how the algorithm can be used to efficiently estimate the key dependent correlation distribution of a linear approximation, facilitating advanced linear attacks. We apply the algorithm to 17 different ciphers, and present new and improved results on several of these.

The Structure of Wiggins' Interpersonal Circumplex: Cross-Cultural Studies

1999 ◽  
Vol 15 (3) ◽  
pp. 196-205 ◽  
Author(s):  
Rosario Martínez-Arias ◽  
Fernando Silva ◽  
Ma Teresa Díaz-Hidalgo ◽  
Generós Ortet ◽  
Micaela Moro
Keyword(s):  
Cultural Studies ◽  
Cross Cultural ◽  
The Other ◽  
Spanish Version ◽  
Interpersonal Circumplex ◽  
Research Groups ◽  
Independent Research ◽  
Research Results ◽  
Cross Cultural Studies

Summary: This paper presents the results obtained in Spain with The Interpersonal Adjective Scales of J.S. Wiggins (1995) concerning the variables' structure. There are two Spanish versions of IAS, developed by two independent research groups who were not aware of each other's work. One of these versions was published as an assessment test in 1996. Results from the other group have remained unpublished to date. The set of results presented here compares three sources of data: the original American manual (from Wiggins and collaborators), the Spanish manual (already published), and the new IAS (our own research). Results can be considered satisfactory since, broadly speaking, the inner structure of the original instrument is well replicated in the Spanish version.

ANALISIS VARIABEL YANG BERPENGARUH TERHADAP KINERJA PERUSAHAAN DI BURSA EFEK INDONESIA

2019 ◽  
Author(s):  
SUSENO - SUSENO
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Stock Exchange ◽  
T Test ◽  
The Other ◽  
Financial Leverage ◽  
F Test ◽  
Research Results ◽  
Independent Variables ◽  
Influential Variable

ANALISIS VARIABEL YANG BERPENGARUH TERHADAP KINERJA PERUSAHAAN DI BURSA EFEK INDONESIAOleh : Suseno STIE SATRIA Purwokerto ABSTRACT The aims of the research are (1) to analyze influence of age, scale, financial leverage, and profitability to performance of firms at The Indonesian Stock Exchange. (2) to determine the most influential variable on the performance of the firms. Hypotheses proposed in this research were: (1) Age, Scales, Financial Leverage, Profitability influences the performance of firms, (2) Age influences the performance of firms, (3) Scales influences the performance of firms, (4) Financial Leverage influences the performance of firms, (5) Profitability influences the performance of firms. Instrument of analysis employed in the research was multiple linear regression with t test and F test.The results of analyses of t test showed that profitability did not influence the performance of the firms. It was indicated by the value of computed t which was smaller than the value of t table. Meanwhile, the t test of age, scale and financial leverage indicated that the value of computed t > t table. It means that these variables (scale and financial leverage) influenced the performance of the firms. The F test showed that the independent variables of age, scale, financial leverage and profitability as a whole significantly influenced the performance of the firms. It was indicated by the calculated F > the value of F table, the value the age computed t which was smaller than the value of -t table..Based on the research results that age and profitability do not influence the performance of the firms, it is suggested that investors should not pay any attention to those variables. On the other hand, they should pay attention to the variables of scale and financial leverage. It is recommended that for further research should include longer periode of the sample.

scholarly journals A Discontinuity of the Energy of Quantum Walk in Impurities

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1134
Author(s):  
Kenta Higuchi ◽  
Takashi Komatsu ◽  
Norio Konno ◽  
Hisashi Morioka ◽  
Etsuo Segawa
Keyword(s):  
Unit Circle ◽  
Stationary State ◽  
Discrete Time ◽  
Quantum Walk ◽  
Time Limit ◽  
The Other ◽  
Unitary Matrix ◽  
Initial State ◽  
Time Quantum ◽  
Long Time

We consider the discrete-time quantum walk whose local dynamics is denoted by a common unitary matrix C at the perturbed region {0,1,⋯,M−1} and free at the other positions. We obtain the stationary state with a bounded initial state. The initial state is set so that the perturbed region receives the inflow ωn at time n(|ω|=1). From this expression, we compute the scattering on the surface of −1 and M and also compute the quantity how quantum walker accumulates in the perturbed region; namely, the energy of the quantum walk, in the long time limit. The frequency of the initial state of the influence to the energy is symmetric on the unit circle in the complex plain. We find a discontinuity of the energy with respect to the frequency of the inflow.

Numerical Simulation Research on the Shape of Top Coal Drawn-Body in Gently Inclined Seam

2012 ◽  
Vol 468-471 ◽  
pp. 2248-2254
Author(s):  
Qiang Li ◽  
Wan Kui Bu ◽  
Hui Xu ◽  
Xiao Bo Song
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Random Medium ◽  
Body Movement ◽  
The Other ◽  
Simulation Research ◽  
Research Results ◽  
Shape Equation ◽  
The Difference ◽  
Meso Scale

The numerical model of top coal drawing in gently inclined seam is built based on PFC2d software. By comparing with the theory of drawn-body movement law, it can be obtained that the shape of top coal drawn-body accords with the theory of random medium movement. The research results show that the form of the shape equation of top coal drawn-body is uniform while the top coal caving angle is different. On the other hand, with the difference of top coal caving angle and drawing height, the shape of top coal drawn-body is differential at the meso scale, which depends on the parameters of the shape equation of top coal drawn-body.

scholarly journals Pengujian Zeolit Alam Mordenit Sebagai Penjerap Proses Pendegradasian Kandungan Amonium di dalam Air Tambak

2020 ◽  
Vol 21 (1) ◽  
pp. 49-55
Author(s):  
Nuryoto Nuryoto ◽  
Teguh Kurniawan ◽  
Indar Kustiningsih
Keyword(s):  
Particle Size ◽  
Natural Zeolite ◽  
The Other ◽  
Ammonium Concentration ◽  
Small Fish ◽  
Natural Zeolites ◽  
Absorption Time ◽  
Adsorption Time ◽  
Research Results ◽  
Other Hand

ABSTRACTIndonesia has an abundant quantity of natural zeolites that have not yet been utilized maximally. On the other hand, fishpond farmers have a problem regarding the presence of ammonium in the fishpond water which will negatively impact to survival of fish, especially small fish. To solve this problem, this research was utilizing natural zeolite to degrade ammonium in the fishpond water. This research aimed to test mordenite natural zeolite from Bayah as an adsorbent to collaborate some variables impact to reach more maximal adsorption. The variables that were used to be observed were: mordenite natural zeolite from Bayah as an adsorbent which has been activated by 1-7 N H2SO4 and the other was without activation, ammonium concentration of 80-800 ppm, the particle size of adsorbent of 80 and 150 mesh, stirring speed of 600 and 800 rpm, and without stirring by duration adsorption time of 60 minutes. The research results showed that mordenite natural zeolite after activated was able to adsorb of 100% ammonium, while for the mordenite natural zeolite from Bayah without stirring was of 80%, by the same absorption time. These results will give significant benefits for fishpond farmers to increase their productivity because of the increase in fish survival.Keywords: adsorption, adsorbent, zeolite, amoniumABSTRAKKandungan zeolit alam di Indonesia cukup melimpah dan belum termanfaatkan secara maksimal. Pada sisi lain petani tambak dihadapkan pada masalah terdapatnya kandungan amonium di dalam air tambak, yang akan berdampak negatif bagi keberlangsungan hidup ikan, terutama ikan yang masih kecil. Penelitian ini mencoba memanfaatkan zeolit alam guna mendegradasi kandungan amonium dalam air tambak. Tujuan penelitian ini adalah melakukan pengujian terhadap zeolit alam mordenit dari Bayah sebagai adsorben, baik dilakukan dengan pengadukan maupun tanpa pengadukan, serta mengkolaborasi beberapa variabel yang berpengaruh agar hasil adsorpsi lebih maksimal. Observasi dilakukan dengan zeolit alam mordenit dari Bayah yang telah diaktivasi dengan 1-7 N H2SO4 maupun tanpa aktivasi, rentang konsentrasi larutan amonium 80-800 ppm, ukuran partikel adsorben 80 dan 150 mesh, kecepatan pengadukan 600 dan 800 rpm, dan tanpa pengadukan serta lamanya waktu penyerapan 60 menit. Hasil penelitian menunjukan hasil yang sangat baik, dan secara umum zeolit alam mordenit Bayah teraktivasi telah mampu melakukan adsorpsi amonium sebesar 100%, sedangkan untuk zeolit alam mordenit Bayah tanpa pengadukan sebesar 80% pada waktu adsorpsi yang sama.Kata kunci: adsorpsi, adsorben, zeolit, amonium

scholarly journals Applying transfer entropy approach to investigate the information flow among ASEAN stock markets

2020 ◽  
Vol 4 (1) ◽  
pp. First
Author(s):  
Tran Thi Tuan Anh
Keyword(s):  
Information Flow ◽  
Stock Markets ◽  
Investment Strategy ◽  
The Philippines ◽  
Transfer Entropy ◽  
The Other ◽  
Information Flows ◽  
Research Results ◽  
Region Data ◽  
Asean Countries

This paper uses transfer entropy to measure and identify the information flows between stock markets in the ASEAN region. Data on daily closing stock indices, including Vietnam, the Philippines, Malaysia, Indonesia, Thailand, and Singapore, are collected for the period from March 2012 to October 2019 to calculate these transfer entropies. The research results of this article can be considered in two aspects: one is, how information flow originating from one market will be accepted by other markets and secondly, information flow that markets receive. From the perspective of incoming transfer entropy, Vietnam is the country most affected by information from the other ASEAN markets while Indonesia and Malaysia are the least affected. In terms of outgoing entropy, Thailand is the largest source of information flow to the ASEAN markets. Malaysia and the Philippines are the two countries that receive minor information impact from other countries. The research also reveals that the Singapore stock market is rather separate from the other ASEAN countries. The research results also imply that, for investors and policymakers, defining the information flows among ASEAN stock markets can help to predict market movements, thereby developing a suitable investment strategy or establishing appropriate management policies.

Optimization Design of Beam Based on Genetic Algorithm

2010 ◽  
Vol 163-167 ◽  
pp. 2365-2368 ◽  
Author(s):  
Shu Ling Qiao ◽  
Zhi Jun Han
Keyword(s):  
Genetic Algorithm ◽  
Objective Function ◽  
Linear Approximation ◽  
Approximation Method ◽  
Optimization Design ◽  
Mathematic Model ◽  
Processing Method ◽  
Fast Convergence ◽  
The Other ◽  
Linear Approximation Method

In this paper, determinate beam and indeterminate beam with multiple span are optimized by using genetic algorithm, the mathematic model of optimize beam is built and the processing method of constraint conditions is given. The examples show that the algorithm could be used for optimizing determinate structure, and also optimizing indeterminate structure. Compared to the linear approximation method, genetic algorithm has advantages of being simple, easy, fast convergence and has no use for changing the objective function and constraint conditions to linearity or other processing. Its results agree with linear approximation method’s. It is the other method that can be adopt in engineering field.

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