scholarly journals A Brief Review on Methodology of Cryptanalysis

Author(s):  
K V Srinivasa Rao ◽  
M M Naidu ◽  
R. Satya Prasad

Cryptanalysis comes into deferent forms in order to support that rigorous analysis of the structure cryptographic primitive to evaluate and verify its claimed security margins. This analysis will follow the attack models represented previously in order to exploit possible weakness in the primitive. Thus, achieving the associated attack goals which will vary from a distinguishing attack to a total break that is defined based on the security margins or claims of the primitive under study. For example, for a hash function, total break constitutes finding a collision or obtaining the message from the hash value. While in block ciphers it revolves around recovering the secret key. When it comes to the claimed security margins, the design approaches will follow certain security models as in provable security or practical security or a mixture of both. The role of cryptanalyst is to subject these primitives to different existing categories of cryptanalysis approaches and tailor new ones that will push the design’s security margins if possible to new limits where these attacks are not applicable any more This chapter will introduce the prominent methods of cryptanalysis that utilize certain behavior in the cipher structure. Such behavior disturbs the assumed randomness of the output or the cipher text. This Paper will explore the basic definitions of prominent cryptanalysis methods that targets the specific structure of a cipher namely differential and linear cryptanalysis and their different variants. It will also discuss other potential crytpanalytic methods that are usually used in symmetric-key ciphers analysis especially block ciphers.

Author(s):  
А.С. Сосков ◽  
Б.Я. Рябко

Рассмотрено применение атаки различения на ряд легковесных блочных шифров, основанных на ARX-операциях (сложение по модулю, циклический сдвиг и исключающее ИЛИ). Представлены экспериментальные результаты и теоретические оценки устойчивости легковесных шифров Speck, Simon, Simeck, HIGHT, LEA к атаке различения. Вывод, что семейство шифров Simeck не выдерживает эту атаку, сделан на основе прогнозов, полученных путем экстраполяции экспериментальных данных. The distinguishing attack on modern lightweight ARX-based block ciphers was applied. Distinguishing attack is any form of cryptanalysis on data encrypted by a cipher that allows an attacker distinguishing the encrypted data from random data. Purpose. Modern symmetric-key ciphers must be designed to be immune to such an attack. The purpose of the work was to estimate the resistance of lightweight ciphers Speck, Simon, Simeck, HIGHT, and LEA to a distinguishing attack. Methodology. We note that these ciphers are iterated block ciphers. It is means that they transform blocks of plain text into blocks of cipher text by using the cyclically repeated invertible function known as the round function where each iteration is to be referred as a round. We have experimentally found a maximum number of rounds where encrypted data looked like random bit-sequence by using statistical test “Book Stack”. Then we extrapolated the theoretical length required for a successful distinguishing attack on cipher with full-number rounds by a polynomial of a low degree. Note that cryptography attack is considered as successful if the length of the encrypted sequence is less than the length 2K (K — key size). Originality/value. Our experiments and estimations show, that Simeck with 48bit block size and 96-bit key size is not immune to distinguishing attack. We recommended increasing the number of rounds by 15–20% in order to improve the reliability of the Simeck 48/96.


Author(s):  
Akinori Hosoyamada ◽  
Tetsu Iwata

Recent results on quantum cryptanalysis show that some symmetric key schemes can be broken in polynomial time even if they are proven to be secure in the classical setting. Liskov, Rivest, and Wagner showed that secure tweakable block ciphers can be constructed from secure block ciphers in the classical setting. However, Kaplan et al. showed that their scheme can be broken by polynomial time quantum superposition attacks, even if underlying block ciphers are quantum-secure. Since then, it remains open if there exists a mode of block ciphers to build quantum-secure tweakable block ciphers. This paper settles the problem in the reduction-based provable security paradigm. We show the first design of quantum-secure tweakable block ciphers based on quantum-secure block ciphers, and present a provable security bound. Our construction is simple, and when instantiated with a quantum-secure n-bit block cipher, it is secure against attacks that query arbitrary quantum superpositions of plaintexts and tweaks up to O(2n/6) quantum queries. Our security proofs use the compressed oracle technique introduced by Zhandry. More precisely, we use an alternative formalization of the technique introduced by Hosoyamada and Iwata.


2017 ◽  
Vol 10 (2) ◽  
pp. 345-351
Author(s):  
Junestarfield Kynshi ◽  
Deepa Jose

This paper aims to solve the problems of the existing technique of the content based double encryption algorithm using symmetric key cryptography. Simple binary addition, folding method and logical XOR operation are used to encrypt the content of a plaintext as well as the secret key.This algorithm helps to achieve the secure transfer of data throught the network. It solved the problems of the existing algorithm and provides a better solution. The plaintext are encrypted using the above methods and produce a cipher text. The secret key is encrypted and shared through secure network and without knowing the secret key it is difficult to decipher the text. As per expected, enhanced encryption algorithm gives better result than the existing encryption algorithm.


Author(s):  
Anchal Goyal ◽  
Deepinder Kaur

In this dissertation a PicPass algorithm is proposed for the solution of Key Exchange problem using Symmetric and Asymmetric key cryptography. Diffie and Hellman proposed an algorithm for key exchange. But this algorithm suffers from Man-in middle attack. So to overcome this problem Seo proposed another algorithm that uses text password for the agreement between two parties. But again the password suffers from offline dictionary attack. In this, a PicPass Protocol i.e. picture is used as a password to make an agreement between two parties. The protocol contains two function i.e. picture function as well as distortion function is used to make picture in a compact size and then it is sent to receiver. Firstly the sender encrypts the Plain Text using Secret Picture and creates the Cipher Text using Symmetric key cryptography.Then the Secret Picture will be encrypted by covered picture resulting into Encrypted Picture.Now the Cipher Text and Encrypted Picture will be placed into digital envolpe and then the envelope will be send to the receiver. The receiver will receive the digital envelope, open it and then decrypt the Encrypted Picture using his Key Picture. This will result the receiver to get the Secret Picture. Now the receiver will open the Cipher Text using the Secret Picture and get the Plain Text. In between if any person wants to predict the Encrypted Picture then he cannot guess as the picture will only be decrypted using the Secret Key which will be only with the receiver. So in this dissertation, a picture is used as a password to authenticate key exchange is that gives practical solution against offline dictionary attacks only by using both private and public key cryptography.


In this paper we present an upgraded technique of coding a message using Multilevel Cryptosystem based on Four square Cipher, Mono alphabetic Substitution Cipher and Columnar Transposition cipher subjected to Graph labeling. We send our Cipher text in the form of graph pattern which admits Root cube mean labeling. Further by using the secret key the receiver decrypts the edge labels which is shared by the sender. Here we employ Symmetric key cryptosystem for both encryption and decryption of messages as both the sender as well as thereceiver shares the same key for encryption and decryption of messages. In this research work we performed Multilevel Cryptographic technique together with Graph Labeling concept to save the messages from third party or Hackers ensuring secure transmission of messages


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Ping Zhang ◽  
Qian Yuan

The Even–Mansour cipher has been widely used in block ciphers and lightweight symmetric-key ciphers because of its simple structure and strict provable security. Its research has been a hot topic in cryptography. This paper focuses on the problem to minimize the key material of the Even–Mansour cipher while its security bound remains essentially the same. We introduce four structures of the Even–Mansour cipher with a short key and derive their security by Patarin’s H-coefficients technique. These four structures are proven secure up to O˜2k/μ adversarial queries, where k is the bit length of the key material and μ is the maximal multiplicity. Then, we apply them to lightweight authenticated encryption modes and prove their security up to about minb/2,c,k−log μ-bit adversarial queries, where b is the size of the permutation and c is the capacity of the permutation. Finally, we leave it as an open problem to settle the security of the t-round iterated Even–Mansour cipher with short keys.


Author(s):  
Jeroen Pijnenburg ◽  
Bertram Poettering

A popular cryptographic option to implement Hierarchical Access Control in organizations is to combine a key assignment scheme with a symmetric encryption scheme. In brief, key assignment associates with each object in the hierarchy a unique symmetric key, and provides all higher-ranked “authorized” subjects with a method to recover it. This setup allows for encrypting the payloads associated with the objects so that they can be accessed by the authorized and remain inaccessible for the unauthorized. Both key assignment and symmetric encryption have been researched for roughly four decades now, and a plethora of efficient constructions have been the result. Surprisingly, a treatment of the joint primitive (key assignment combined with encryption, as used in practice) in the framework of provable security was conducted only very recently, leading to a publication in ToSC 2018(4). We first carefully revisit this publication. We then argue that there are actually two standard use cases for the combined primitive, which also require individual treatment. We correspondingly propose a fresh set of security models and provably secure constructions for each of them. Perhaps surprisingly, the two constructions call for different symmetric encryption primitives: While standard AEAD is the right tool for the one, we identify a less common tool called Encryptment as best fitting the other.


Author(s):  
Er. Krishan Kumar ◽  
Nidhi Singla

In this dissertation a PicPass algorithm is proposed for the solution of Key Exchange problem using Symmetric and Asymmetric key cryptography. Diffie and Hellman proposed an algorithm for key exchange. But this algorithm suffers from Man-in middle attack. So to overcome this problem Seo proposed another algorithm that uses text password for the agreement between two parties. But again the password suffers from offline dictionary attack. In this, a PicPass Protocol i.e. picture is used as a password to make an agreement between two parties. The protocol contains two function i.e. picture function as well as distortion function is used to make picture in a compact size and then it is sent to receiver. Firstly the sender encrypts the Plain Text using Secret Picture and creates the Cipher Text using Symmetric key cryptography. Then the Secret Picture will be encrypted by covered picture resulting into Encrypted Picture. Now the Cipher Text and Encrypted Picture will be placed into digital envelope and then the envelope will be send to the receiver. The receiver will receive the digital envelope, open it and then decrypt the Encrypted Picture using his Key Picture. This will result the receiver to get the Secret Picture. Now the receiver will open the Cipher Text using the Secret Picture and get the Plain Text. In between if any person wants to predict the Encrypted Picture then he cannot guess as the picture will only be decrypted using the Secret Key which will be only with the receiver. So in this dissertation, a picture is used as a password to authenticate key exchange is that gives practical solution against offline dictionary attacks only by using both private and public key cryptography.


2021 ◽  
Vol 10 (16) ◽  
pp. 3457
Author(s):  
Kamila Kolanska ◽  
Sofiane Bendifallah ◽  
Geoffroy Canlorbe ◽  
Arsène Mekinian ◽  
Cyril Touboul ◽  
...  

The molecular responses to hormonal stimuli in the endometrium are modulated at the transcriptional and post-transcriptional stages. Any imbalance in cellular and molecular endometrial homeostasis may lead to gynecological disorders. MicroRNAs (miRNAs) are involved in a wide variety of physiological mechanisms and their expression patterns in the endometrium are currently attracting a lot of interest. miRNA regulation could be hormone dependent. Conversely, miRNAs could regulate the action of sexual hormones. Modifications to miRNA expression in pathological situations could either be a cause or a result of the existing pathology. The complexity of miRNA actions and the diversity of signaling pathways controlled by numerous miRNAs require rigorous analysis and findings need to be interpreted with caution. Alteration of miRNA expression in women with endometriosis has been reported. Thus, a potential diagnostic test supported by a specific miRNA signature could contribute to early diagnosis and a change in the therapeutic paradigm. Similarly, specific miRNA profile signatures are expected for RIF and endometrial cancer, with direct implications for associated therapies for RIF and adjuvant therapies for endometrial cancer. Advances in targeted therapies based on the regulation of miRNA expression are under evaluation.


2021 ◽  
Vol 11 (11) ◽  
pp. 4776
Author(s):  
Kyungbae Jang ◽  
Gyeongju Song ◽  
Hyunjun Kim ◽  
Hyeokdong Kwon ◽  
Hyunji Kim ◽  
...  

Grover search algorithm is the most representative quantum attack method that threatens the security of symmetric key cryptography. If the Grover search algorithm is applied to symmetric key cryptography, the security level of target symmetric key cryptography can be lowered from n-bit to n2-bit. When applying Grover’s search algorithm to the block cipher that is the target of potential quantum attacks, the target block cipher must be implemented as quantum circuits. Starting with the AES block cipher, a number of works have been conducted to optimize and implement target block ciphers into quantum circuits. Recently, many studies have been published to implement lightweight block ciphers as quantum circuits. In this paper, we present optimal quantum circuit designs of symmetric key cryptography, including PRESENT and GIFT block ciphers. The proposed method optimized PRESENT and GIFT block ciphers by minimizing qubits, quantum gates, and circuit depth. We compare proposed PRESENT and GIFT quantum circuits with other results of lightweight block cipher implementations in quantum circuits. Finally, quantum resources of PRESENT and GIFT block ciphers required for the oracle of the Grover search algorithm were estimated.


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