scholarly journals A New Automatic Tool Searching for Impossible Differential of NIST Candidate ACE

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1576
Author(s):  
Jingyi Liu ◽  
Guoqiang Liu ◽  
Longjiang Qu
Keyword(s):  
Characteristic Matrix ◽  
Differential Attack ◽  
Optimal Permutation ◽  
The Usa ◽  
Standardization Process ◽  
Impossible Differential ◽  
Automatic Tool ◽  
Ace Algorithm ◽  
Impossible Differentials ◽  
Impossible Differential Cryptanalysis

The ACE algorithm is a candidate of the Lightweight Cryptography standardization process started by the National Institute of Standards and Technology (NIST) of the USA that passed the first round and successfully entered the second round. It is designed to achieve a balance between hardware cost and software efficiency for both authenticated encryption with associated data (AEAD) and hashing functionalities. This paper focuses on the impossible differential attack against the ACE permutation, which is the core component of the ACE algorithm. Based on the method of characteristic matrix, we build an automatic searching algorithm that can be used to search for structural impossible differentials and give the optimal permutation for ACE permutation and other SPN ciphers. We prove that there is no impossible differential of ACE permutation longer than 9 steps and construct two 8-step impossible differentials. In the end, we give the optimal word permutation against impossible differential cryptanalysis, which is π′=(2,4,1,0,3), and a safer word XOR structure of ACE permutation.

scholarly journals On the Complexity of Impossible Differential Cryptanalysis

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Qianqian Yang ◽  
Lei Hu ◽  
Danping Shi ◽  
Yosuke Todo ◽  
Siwei Sun
Keyword(s):  
Time Complexity ◽  
Differential Analysis ◽  
Differential Attack ◽  
Symmetric Key ◽  
Impossible Differential ◽  
Complexity Estimation ◽  
Impossible Differential Attack ◽  
Differential Attacks ◽  
Impossible Differentials ◽  
Impossible Differential Cryptanalysis

While impossible differential attack is one of the most well-known and familiar techniques for symmetric-key cryptanalysts, its subtlety and complicacy make the construction and verification of such attacks difficult and error-prone. We introduce a new set of notations for impossible differential analysis. These notations lead to unified formulas for estimation of data complexities of ordinary impossible differential attacks and attacks employing multiple impossible differentials. We also identify an interesting point from the new formulas: in most cases, the data complexity is only related to the form of the underlying distinguisher and has nothing to do with how the differences at the beginning and the end of the distinguisher propagate in the outer rounds. We check the formulas with some examples, and the results are all matching. Since the estimation of the time complexity is flawed in some situations, in this work, we show under which condition the formula is valid and give a simple time complexity estimation for impossible differential attack which is always achievable.

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.

scholarly journals Cryptanalysis of Reduced round SKINNY Block Cipher

2018 ◽  
pp. 124-162 ◽  
Author(s):  
Sadegh Sadeghi ◽  
Tahereh Mohammadi ◽  
Nasour Bagheri
Keyword(s):  
Mixed Integer Linear Programming ◽  
Block Cipher ◽  
Mixed Integer ◽  
Differential Attack ◽  
Key Recovery ◽  
Zero Correlation ◽  
Impossible Differential ◽  
Key Recovery Attack ◽  
Correlation Attacks ◽  
Impossible Differential Cryptanalysis

SKINNY is a family of lightweight tweakable block ciphers designed to have the smallest hardware footprint. In this paper, we present zero-correlation linear approximations and the related-tweakey impossible differential characteristics for different versions of SKINNY .We utilize Mixed Integer Linear Programming (MILP) to search all zero-correlation linear distinguishers for all variants of SKINNY, where the longest distinguisher found reaches 10 rounds. Using a 9-round characteristic, we present 14 and 18-round zero correlation attacks on SKINNY-64-64 and SKINNY- 64-128, respectively. Also, for SKINNY-n-n and SKINNY-n-2n, we construct 13 and 15-round related-tweakey impossible differential characteristics, respectively. Utilizing these characteristics, we propose 23-round related-tweakey impossible differential cryptanalysis by applying the key recovery attack for SKINNY-n-2n and 19-round attack for SKINNY-n-n. To the best of our knowledge, the presented zero-correlation characteristics in this paper are the first attempt to investigate the security of SKINNY against this attack and the results on the related-tweakey impossible differential attack are the best reported ones.

scholarly journals Multiple Impossible Differentials Cryptanalysis on 7-Round ARIA-192

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Zi-Long Jiang ◽  
Chen-Hui Jin
Keyword(s):  
Efficient Algorithm ◽  
Differential Cryptanalysis ◽  
Time Data ◽  
Impossible Differential ◽  
Sieving Process ◽  
Impossible Differentials ◽  
Impossible Differential Cryptanalysis

This paper studies the security of 7-round ARIA-192 against multiple impossible differentials cryptanalysis. We propose six special 4-round impossible differentials which have the same input difference and different output difference with the maximum number of nonzero common bytes. Based on these differentials, we construct six attack trails including the maximum number of common subkey bytes. Under such circumstances, we utilize an efficient sieving process to improve the efficiency of eliminating common subkeys; therefore, both data and time complexities are reduced. Furthermore, we also present an efficient algorithm to recover the master key via guess-and-determine technique. Taking advantage of the above advances, we have obtained the best result so far for impossible differential cryptanalysis of ARIA-192, with time, data, and memory complexities being 2189.8 7-round ARIA encryptions, 2116.6 chosen plaintexts, and 2139.3 bytes, respectively.

Impossible Differential Cryptanalysis of LBlock Code

2014 ◽  
Vol 35 (6) ◽  
pp. 1516-1519
Author(s):  
Jian-sheng Guo ◽  
Wei Luo ◽  
Lei Zhang ◽  
Yuan-bo Guo
Keyword(s):  
Differential Cryptanalysis ◽  
Impossible Differential ◽  
Impossible Differential Cryptanalysis

Impossible Differential Cryptanalysis of Reduced-Round Midori64 Block Cipher

2017 ◽  
Author(s):  
Aein Rezaei Shahmirzadi ◽  
Seyyed Arash Azimi ◽  
Mahmoud Salmasizadeh ◽  
Javad Mohajeri ◽  
Mohammad Reza Aref
Keyword(s):  
Block Cipher ◽  
Differential Cryptanalysis ◽  
Impossible Differential ◽  
Impossible Differential Cryptanalysis
Sign in / Sign up

Export Citation Format

Share Document