Key Generation for Vigenere Ciphering Based on Genetic Algorithm (original) (raw)
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Modified Vigenère cipher algorithm based on new key generation method
Indonesian Journal of Electrical Engineering and Computer Science, 2022
Nowadays, as communication and network technologies evolve in modern life, ensuring the confidentiality of a cryptography system has become a critical requirement. The Vigenère cipher is attracting the attention of cryptography specialists, although the Vigenère cipher algorithm has a problem. The problem is due to a repeating encryption key. As a result of the multiple cryptographic approaches described in the literature, this paper proposes a novel encryption strategy for safe and secure data exchange by utilizing a new key generation process. The proposed encryption approach avoids the issue of repeating keys. Additionally, the classic Vigenère cipher encrypts the plaintext using a 26x26 Vigenère table, the researcher modified the original Vigenère table to 95x95, which adds more potential letters, mathematical symbols, numerals, and punctuation to a standard QWERTY keyboard layout. Additionally, the researcher added case sensitivity. To observe the performance of the proposed method, the index of coincidence and entropy have been calculated. The obtained results confirm the high performance of the proposed algorithm in comparison to the other algorithms used in this paper. The primary goal of this paper is to make cryptanalysis extremely complex and to promote data security.
2021 7th International Conference on Computer and Communications (ICCC)
In recent years, many modifications have been done to combat the weaknesses of the Vigenè re Cipher Algorithm. Several studies have been carried out to rectify the flaw of the algorithm's repeating key nature by increasing the key length equal to that of the plain text. However, some characters cannot be encrypted due to the limited set of characters in the key. This paper modified the algorithm's key generation process using a Pseudo-Random Number Generator to improve the algorithm's security and expanded the table of characters to up to 190 characters. The results show that based on Monobit examination and frequency analysis, the repeating nature of the key is nonexistent, and the generated key can be used to encrypt a larger set of characters. The ciphertext has a low IC value of 0.030, which is similar to a random string and polyalphabetic cipher with an IC value of 0.038 but not equal to a monoalphabetic cipher with an IC value of 0.065. Results show that the modified version of the algorithm performs better than some of the recent studies conducted on it
Implication of Genetic Algorithm in Cryptography to Enhance Security
International Journal of Advanced Computer Science and Applications, 2018
In today's age of information technology secure transmission of information is a big challenge. Symmetric and asymmetric cryptosystems are not appropriate for high level of security. Modern hash function based systems are better than traditional systems but the complex algorithms of generating invertible functions are very time consuming. In traditional systems data is being encrypted with the key but still there are possibilities of eavesdrop the key and altered text. Therefore, key must be strong and unpredictable, so a method has been proposed which take the advantage of theory of natural selection. Genetic Algorithms are used to solve many problems by modeling simplified genetic processes and are considered as a class of optimization algorithms. By using Genetic Algorithm the strength of the key is improved that ultimately make the whole algorithm good enough. In the proposed method, data is encrypted by a number of steps. First, a key is generated through random number generator and by applying genetic operations. Next, data is diffused by genetic operators and then logical operators are performed between the diffused data and the key to encrypt the data. Finally, a comparative study has been carried out between our proposed method and two other cryptographic algorithms. It has been observed that the proposed algorithm has better results in terms of the key strength but is less computational efficient than other two.
Dynamic Key generation for Cryptographic Process using Genetic Algorithm
IJCSIS Vol 17 No 4 April Issue, 2019
Usage of an artistic technique for transforming the readable information into unreadable form of the information, referred as encryption and the vice verse, referred as decryption are collectively represented as cryptography. In this paper, the cryptographical key, the base for encryption and decryption, is generated by applying the genetic algorithm. Almost all tasks are done on random generation basis. Starting with the population size, gene count in a chromosome are generated randomly. Fitness function is applied on the population for selecting the strong chromosomes. This process may reduce the size of population which are considered for the genetic process. Crossovering parents and genes are selected on random basis. Crossovered chromosomes are taken for the mutation process. In mutation, the mutation count and position are selected on random basis. Fitness function is applied to select the strong chromosomes for enriching the population. After repeating the genetic process in a random count, the key value is selected from the strong chromosome set in a random way. This key is tested with AES algorithm for performing the encryption and decryption process. The cryptanalysis is done on processing time, entropy along with confusion matrix. From this, it is clear that the key used for cryptography is stronger to secure the data.
International Journal of Computer Applications, 2021
Vigenère cipher is an ancient elementary method that uses a series of Caesar shifting for encrypting plaintext to ciphertext protecting it from adversaries. However, a frequency analysis attack is vulnerable in this type of cipher technique. This paper aims to enhance the security of the Vigenère cipher in a hybrid cryptosystem using a randomized approach including pseudorandom substitution, rearranging, padding, etc. In this approach, a complex key generation algorithm is used that generates a pair of subkeys from an input key. One of the subkeys, Subkey1 is used to generate an intermediate ciphertext. The other key, Subkey2 is used to further scramble the ciphertext. The slightest change in the input symmetric key produces an entirely different key pair. Hence, different encrypted results. It also increases the ranges of characters that Vigenère cipher can encrypt by including all ASCII and extended ASCII. Finally, the symmetric key is encrypted with the public key of RSA solving the key distribution problem of the symmetric cipher. This enhanced and modified Vigenère cipher in the hybrid cryptosystem overcomes all limitations of classical cipher and acts as a bridge between classical and modern cryptography.
A Study on Cryptography using Genetic Algorithm
International Journal of Computer Applications, 2015
Cryptography is a basic tool for protection and securing data. Security provides safety, reliability and accuracy. Genetic Algorithm (GA) is typically used to obtain solution for optimization and search problems. This paper presents application of GA in the field of cryptography. The selection of key in the field ofpublic key cryptography is a selection process in which keys can be categorized on the basis of their fitness function, making GA a better candidate for the key generation. We propose a new approach for e-security applications using the concept of genetic algorithms with pseudorandom sequence to encrypt and decrypt data stream. Many different image encryption methods have been proposed to keep the security of these images. Image encryption algorithms try to convert an image to another image that is hard to understand.
A cryptanalytic attack on Vigenère cipher using genetic algorithm
2011 IEEE Conference on Open Systems, 2011
With the exponential growth of networked system and its applications such as e-commerce, the demand for effective internet security is increasing. Cryptology is the science and study of systems for secret communication. It consists of two complementary fields of study: cryptography and cryptanalysis. In this paper the cryptanalysis of a poly alphabetic substitution cipher (Vigenère cipher) by applying genetic algorithms is presented. The applicability of genetic algorithms for searching the key space of encryption scheme is studied. The frequency analysis is used as an essential factor in the objective function.
A Literature Survey on the Usage of Genetic Algorithms In Recent cryptography Researches
This paper will take a brief look at the usage of genetic algorithms in cryptography. Since there is no standard classification, this paper classified the usage into three categories according to its application and usage, they are: The usage of genetic algorithm in key generation, in creating new encryption process, in improving the standard encryption algorithm. And in each approach, its advantages and disadvantages were discussed.
Symmetric Key Encryption using Genetic Algorithm
Genetic Algorithm (GA) is an invaluable tool for solving optimization problems due to its robustness. It does not break even if the inputs are changed slightly or in the presence of a reasonable noise. GA offers significant benefits over other optimization techniques in searching a large state space or n-dimensional surface[1]. In todays information age information sharing and transfer has increased exponentially. With the ever increasing growth of multimedia applications security has become an important issue in the communication of text and images. Encryption has extensive applications in preserving confidentiality of data in Internet applications [2]. There are various proposed methods for image encryption such as quad tree approach, cellular automata [3,5]. With the popularization of Internet and exponential increase in e-commerce transactions security has become an inevitable and an integral part of any e-commerce application. Data integrity, confidentiality, authenticity, non- repudiation have gained tremendous importance and have become important components of information security. There are many risks involved in communication of plain text over Internet. Cryptography is a technique of encoding and decoding messages so that they cannot be interpreted by anybody except the sender and the intended recipient. There are wide applications of GA in solving non-linear optimization problems in various domains. But very few papers exist which exploit the randomness in the algorithm for implementation of security.Chaos theory and entropy have large application in secure data communication and the desired disorder is provided by inherent nature of genetic algorithm [6, 8]. Mohammad Sazzadul Hoque et.al have presented an intrusion detection system by applying GA to efficiently detect various types of network intrusions. They have used evolutionary theory to filterthe traffic data and thus reduce the complexity[9, 10]. There are several papers related to IDS all of which use GA in deriving classification rules [11, 14]. In this paper we have made an attempt to exploit the randomness involved in crossover and mutation processes for generating a secure one time symmetric key for encryption and decryption of messages. The number of crossover points together with number of mutation points dictate the length of the secret key and hence the strength of the algorithm. The algorithm is further strengthened by making it difficult to break by permuting the symmetric key by a predefined permutation factor agreed upon by both the sender and the intended receiver. The randomness together with permutation makes the algorithm robust and hard to break. Finally, the algorithm is implemented in Java and applied for the encryption and decryption of a text file. The methodology is general and can be applied to any file for secure transmission of data.