Automatic search of impossible differentials and zero-correlation linear hulls for ARX ciphers

2018 ◽  
Vol 15 (2) ◽  
pp. 54-66 ◽  
Author(s):  
Kai Zhang ◽  
Jie Guan ◽  
Bin Hu
Keyword(s):  
Zero Correlation ◽  
Automatic Search ◽  
Impossible Differentials

scholarly journals Analysis of AES, SKINNY, and Others with Constraint Programming

2017 ◽  
pp. 281-306 ◽  
Author(s):  
Siwei Sun ◽  
David Gerault ◽  
Pascal Lafourcade ◽  
Qianqian Yang ◽  
Yosuke Todo ◽  
...  
Keyword(s):  
Lower Bound ◽  
Constraint Programming ◽  
Open Problem ◽  
Simple Application ◽  
Programming Technique ◽  
Constraint Solver ◽  
Zero Correlation ◽  
Different Types ◽  
Symmetric Key ◽  
Impossible Differentials

Search for different types of distinguishers are common tasks in symmetrickey cryptanalysis. In this work, we employ the constraint programming (CP) technique to tackle such problems. First, we show that a simple application of the CP approach proposed by Gerault et al. leads to the solution of the open problem of determining the exact lower bound of the number of active S-boxes for 6-round AES-128 in the related-key model. Subsequently, we show that the same approach can be applied in searching for integral distinguishers, impossible differentials, zero-correlation linear approximations, in both the single-key and related-(twea)key model. We implement the method using the open source constraint solver Choco and apply it to the block ciphers PRESENT, SKINNY, and HIGHT (ARX construction). As a result, we find 16 related-tweakey impossible differentials for 12-round SKINNY-64-128 based on which we construct an 18-round attack on SKINNY-64-128 (one target version for the crypto competition https://sites.google.com/site/skinnycipher announced at ASK 2016). Moreover, we show that in some cases, when equipped with proper strategies (ordering heuristic, restart and dynamic branching strategy), the CP approach can be very efficient. Therefore, we suggest that the constraint programming technique should become a convenient tool at hand of the symmetric-key cryptanalysts.

scholarly journals Improved Impossible Differentials and Zero-Correlation Linear Hulls of New Structure III

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jun He ◽  
Xuan Shen ◽  
Guoqiang Liu
Keyword(s):  
Block Cipher ◽  
Characteristic Matrix ◽  
Linear Cryptanalysis ◽  
The Core ◽  
Round Function ◽  
Linear Layer ◽  
Zero Correlation ◽  
Impossible Differential ◽  
Impossible Differentials ◽  
Impossible Differential Cryptanalysis

Impossible differential cryptanalysis and zero-correlation linear cryptanalysis are two kinds of most effective tools for evaluating the security of block ciphers. In those attacks, the core step is to construct a distinguisher as long as possible. In this paper, we focus on the security of New Structure III, which is a kind of block cipher structure with excellent resistance against differential and linear attacks. While the best previous result can only exploit one-round linear layer P to construct impossible differential and zero-correlation linear distinguishers, we try to exploit more rounds to find longer distinguishers. Combining the Miss-in-the-Middle strategy and the characteristic matrix method proposed at EUROCRYPT 2016, we could construct 23-round impossible differentials and zero-correlation linear hulls when the linear layer P satisfies some restricted conditions. To our knowledge, both of them are 1 round longer than the best previous works concerning the two cryptanalytical methods. Furthermore, to show the effectiveness of our distinguishers, the linear layer of the round function is specified to the permutation matrix of block cipher SKINNY which was proposed at CRYPTO 2016. Our results indicate that New Structure III has weaker resistance against impossible differential and zero-correlation linear attacks, though it possesses good differential and linear properties.

Idiographic Dynamics of Positive Affect in GAD

2020 ◽  
Vol 36 (3) ◽  
pp. 500-509
Author(s):  
Hannah G. Bosley ◽  
Devon B. Sandel ◽  
Aaron J. Fisher
Keyword(s):  
Positive Affect ◽  
Structural Equation ◽  
Alternative Hypothesis ◽  
Equation Model ◽  
Aggregated Data ◽  
Regulatory Strategy ◽  
Constant State ◽  
Automatic Search ◽  
Time Lagged ◽  
Exploratory Procedure

Abstract. Generalized anxiety disorder (GAD) is associated with worry and emotion regulation difficulties. The contrast-avoidance model suggests that individuals with GAD use worry to regulate emotion: by worrying, they maintain a constant state of negative affect (NA), avoiding a feared sudden shift into NA. We tested an extension of this model to positive affect (PA). During a week-long ecological momentary assessment (EMA) period, 96 undergraduates with a GAD analog provided four daily measurements of worry, dampening (i.e., PA suppression), and PA. We hypothesized a time-lagged mediation relationship in which higher worry predicts later dampening, and dampening predicts subsequently lower PA. A lag-2 structural equation model was fit to the group-aggregated data and to each individual time-series to test this hypothesis. Although worry and PA were negatively correlated in 87 participants, our model was not supported at the nomothetic level. However, idiographically, our model was well-fit for about a third (38.5%) of participants. We then used automatic search as an idiographic exploratory procedure to detect other time-lagged relationships between these constructs. While 46 individuals exhibited some cross-lagged relationships, no clear pattern emerged across participants. An alternative hypothesis about the speed of the relationship between variables is discussed using contemporaneous correlations of worry, dampening, and PA. Findings suggest heterogeneity in the function of worry as a regulatory strategy, and the importance of temporal scale for detection of time-lagged effects.

Correlation of Phraseological Semantic Fields in Russian Study of Aphorisms

2020 ◽  
pp. 60-71
Author(s):  
Anshelika Korolkova
Keyword(s):  
Negative Correlation ◽  
Semantic Field ◽  
Positive Correlation ◽  
Classical Study ◽  
Semantic Fields ◽  
Zero Correlation ◽  
Russian Study

The article deals with the interconnection and interdependence of phraseological semantic fields of Russian study of aphorisms in synchronic and in diachronic approaches. The correlation of phraseological semantic fields of Russian study of aphorisms is considered as their interdependence due to various factors (linguistic and extra-linguistic ones). The correlation of the phraseological semantic fields of Russian study of aphorisms is manifested in the existence of many antinomies. The natural linguistic antinomies of life / death / immortality or war / peace, or good / evil, or friend / enemy, or villainy / nobility are reflected in Russian aphorisms and have entered the corresponding phraseological semantic fields. The corpus of Russian study of aphorisms containsnot only antinomic aphorisms, but also antinomic relations that extend to the level of language and speech. Therefore, in Russian study of aphorisms there are phraseological semantic fields that implement these antinomies. In addition to the antinomic phraseological semantic fields in the corpus of classical Russian study of aphorisms there are other types of correlations. The keywords (concepts) of many phraseological semantic fields are closely thematically connected. When the number of units from one field is changed, the number of units in another phraseological semantic field also changes. Most phraseological semantic fields of Russian study of aphorisms do not show a zero correlation in either synchronic or diachronic approaches. This is due to, first of all, the universality of the aphoristic theme, with all the ideological and thematic uniqueness of the sayings used by Russian writers. However, a few phraseological and semantic fields of aphorisms by Russian writers may show a negative correlation, which is due to the diversity of the thematic groups that comprise them. A positive correlation of phraseological semantic fields, the most significant in the number of their constituent components, shows deep internal linguistic systemic connections in Russian classical study of aphorisms.

Sign in / Sign up

Export Citation Format

Share Document