A cryptanalytic attack of simplified-AES using ant colony optimization

Ant colony Optimization is a nature-inspired meta-heuristic optimization algorithm that gained a great interest in resolution of combinatorial and numerical optimization problems in many science and engineering domains. The aim of this work was to investigate the use of Ant Colony Optimization in cryptanalysis of Simplified Advanced Encryption Standard (S-AES), using a known plaintext attack. We have defined the essential components of our algorithm such as heuristic value, fitness function and the strategy to update pheromone trails. It is shown from the experimental results that our proposed algorithm allow us to break S-AES cryptosystem after exploring a minimum search space when compared with others techniques and requiring only two plaintext-ciphertext pairs

The Particle Swarm Optimization Based Linear Cryptanalysis of Advanced Encryption Standard Algorithm

The tremendous development in internet technology, wireless communication and the type of internet capable devices has increased the amount of network usage .Millions of users are associated with the network and thus there is need for network security. The sensitive data that is deposited and transmitted on the internet need protection from attackers and eavesdroppers who perform illegal actions. Cryptography algorithms are the key factor of the security mechanisms used for data storage and uninterrupted network transmissions. The data security purely depends on the Cryptography algorithm hence the keys must be managed in a good way. Security mechanisms are developed when a threat to security is identified. To identify the security risk associated with AES algorithm, a computational intelligence based approach for known cryptanalysis of Advanced Encryption Standard algorithm is introduced. Particle swarm optimization based cryptanalysis is used much now a days because of its fast convergence rate. A PSO oriented cryptanalysis technique for breaking the key used in advance encryption standard algorithm is introduced. This approach is for known cipher text-only attack for an AES encryption system, where the key is deduced in a minimum search space in contrast to the Brute Force Attack. The key used in AES can be detected effectively with Particle Swarm Optimization DOI: 10.17762/ijritcc2321-8169.16040

Using Evolving Algorithms to Cryptanalysis Nonlinear Cryptosystems

            في هذا البحث، نتحرى عن استخدام الخوارزميات التطورية (EA's) لتحليل أحد أنظمة التشفير غير الخطية التي تعتمد على وحدة السجلات الزاحفة لتبادل البيانات الخطية (LFSR) باستخدام طريقة هجوم النص المشفر فقط. الخوارزمية الجينية (GA) و خوارزمية خلية النمل ((Ant Colony Optimization (ACO) التي استخدمت في مهاجمة أحد أنظمة التشفير غير الخطية المسماة "Shrinking Generator" باستخدام أطوال مختلفة من النص المشفر وأطوال مختلفة من LFSRs المدمجة أثبتت أدائها الجيد في إيجاد القيم الأولية لل LFSRs المدمجة.            In this paper, new method have been investigated using evolving algorithms (EA's) to cryptanalysis one of the nonlinear stream cipher cryptosystems which depends on the Linear Feedback Shift Register (LFSR) unit by using cipher text-only attack. Genetic Algorithm (GA) and Ant Colony Optimization (ACO) which are used for attacking one of the nonlinear cryptosystems called "shrinking generator" using different lengths of cipher text and different lengths of combined LFSRs. GA and ACO proved their good performance in finding the initial values of the combined LFSRs. This work can be considered as a warning for a stream cipher designer to avoid the weak points, which may be found in the stream cipher, and may be explored by the cryptanalysts. This work can find the optimal solution for text with minimum lengths of 20 characters and 100 iteration were very enough to find the real initial values of key stream

A Hybrid Computational Intelligence based Technique for Automatic Cryptanalysis of Playfair Ciphers

The Playfair cipher is a symmetric key cryptosystem-based on encryption of digrams of letters. The cipher shows higher cryptanalytic complexity compared to mono-alphabetic cipher due to the use of 625 different letter-digrams in encryption instead of 26 letters from Roman alphabets. Population-based techniques like Genetic algorithm (GA) and Swarm intelligence (SI) are more suitable compared to the Brute force approach for cryptanalysis of cipher because of specific and unique structure of its Key Table. This work is an attempt to automate the process of cryptanalysis using hybrid computational intelligence. Multiple particle swarm optimization (MPSO) and GA-based hybrid technique (MPSO-GA) have been proposed and applied in solving Playfair ciphers. The authors have attempted to find the solution key applied in generating Playfair crypts by using the proposed hybrid technique to reduce the exhaustive search space. As per the computed results of the MPSO-GA technique, correct solution was obtained for the Playfair ciphers of 100 to 200 letters length. The proposed technique provided better results compared to either GA or PSO-based technique. Furthermore, the technique was also able to recover partial English text message for short Playfair ciphers of 80 to 120 characters length

A Hybrid Technique for Enhancing Data Security

The worldwide information and technology has an astounding dependency o n data s e c u r i t y . The r i s k fabricated by the interloper has been a maelstrom for forthcoming specialists. Security pl ay s an essential role in governing the data transfer. The primary objective of this paper is to propose a black box approach which generates a modified plain text from the original message. For this purpose, we have used techniques like Perturbation, Swapping and Shifting which will modify the original plain text. Before giving the plain text directly into encryption process, the m o d i f i e d plain text obtained f r o m above techniques will be given as an input. The complexity of breaking the plain text is increased by applying the above techniques. For experimental purpose, w e use AES algorithm for encryption and d e c r y p t i o n and Java is used for implementing t h e proposed a p p r o a c h . © 2018 Academic Press. All Rights Reserved

Improved PSO Algorithm to Attack Transposition Cipher

Cryptanalysis is a complex and mathematically challenging field of study. It takes some data or message, which is called cipher text and attempt to restore its plaintext. This paper attempts to use an improved particle swarm optimization (PSO) to obtain the plaintext from the transposition cipher. This improved method gives a good performance for the PSO algorithm by generating best solution from the best to avoid stability to reach to solution (key). This key is used for breaking transposition cipher

A Hybrid Technique for Enhancing Data Security

The worldwide information and technology has an astounding dependency o n data s e c u r i t y . The r i s k fabricated by the interloper has been a maelstrom for forthcoming specialists. Security pl ay s an essential role in governing the data transfer. The primary objective of this paper is to propose a black box approach which generates a modified plain text from the original message. For this purpose, we have used techniques like Perturbation, Swapping and Shifting which will modify the original plain text. Before giving the plain text directly into encryption process, the m o d i f i e d plain text obtained f r o m above techniques will be given as an input. The complexity of breaking the plain text is increased by applying the above techniques. For experimental purpose, w e use AES algorithm for encryption and d e c r y p t i o n and Java is used for implementing t h e proposed a p p r o a c h . © 2018 Academic Press. All Rights Reserved

Tabu Cryptanalysis of VMPC Stream Cipher

In the era of global informatization, transmitting and storing information in digital form it is very important to ensure an adequate level of security of ciphers used. Cryptanalysis deals with studying the level of security, thus exposing the weakness of theoretical and implemented cryptographic solutions. In this paper cryptanalysis of stream cipher VMPC using Tabu Search is shown. From estimates made on a full version of VMPC cipher we concluded that about 2157 possibilities needs to be checked in order to find the proper one, which would be the best attack known so far

Breaking Data Encryption Standard with a Reduced Number of Rounds Using Metaheuristics Differential Cryptanalysis

This article presents the author’s own metaheuristic cryptanalytic attack based on the use of differential cryptanalysis (DC) methods and memetic algorithms (MA) that improve the local search process through simulated annealing (SA). The suggested attack will be verified on a set of ciphertexts generated with the well-known DES (data encryption standard) reduced to six rounds. The aim of the attack is to guess the last encryption subkey, for each of the two characteristics Ω. Knowing the last subkey, it is possible to recreate the complete encryption key and thus decrypt the cryptogram. The suggested approach makes it possible to automatically reject solutions (keys) that represent the worst fitness function, owing to which we are able to significantly reduce the attack search space. The memetic algorithm (MASA) created in such a way will be compared with other metaheuristic techniques suggested in literature, in particular, with the genetic algorithm (NGA) and the classical differential cryptanalysis attack, in terms of consumption of memory and time needed to guess the key. The article also investigated the entropy of MASA and NGA attacks