Survey: Recent Modifications in Vigenere Cipher (original) (raw)
Vigenere Cipher: Trends, Review and Possible Modifications
Vigenere cipher is one of the earliest known polyalphabetic cipher which was considered secure for a very long time until 1917 when friedman and kasiski were able to break it by determining repeating segments of the ciphertext and using it to determine the length of the key. Once the length of the key is known, the ciphertext could be grouped in columns and treated as a separate caesar cipher which can be solved. Over the years, a lot of modification has been done to inprove the security of the vigenere cipher. This paper presents a review of the vigenere cipher and also discusses various existing modifications.
An Enhanced Vigenere Cipher For Data Security
In today's world the amount of data that is exchanged has increased in the last few years so securing the information has become a crucial task. Cryptography is an art of converting plain text message into unreadable message. Encryption algorithms play an important role in information security systems. Encryption is considered as one of the most powerful tool for secure transmission of data over the communication network. Vigenere technique is an example of polyalphabetic stream cipher; it has various limitations such as Kasiski and Friedman attack to find the length of encryption key. In this paper an enhanced version of traditional vigenere cipher has been proposed that eliminates the chances of Kaisiski and Friedman attack. Proposed technique also provides better security against cryptanalysis and pattern prediction.
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.
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.
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
Modified Vegenere Cipher to Enhance Data Security Using Monoalphabetic Cipher
International Journal of Artificial Intelligence & Robotics (IJAIR), 2019
The rapid progression of exchange data by public networks is important, especially in information security. We need to keep our information safe from attackers or intruders. Furthermore, information security becomes needed for us. Many kind cipher methods of cryptography are improved to secure information such as monoalphabetic cipher and polyalphabetic cipher. Cryptography makes readable messages becoming non-readable messages. One of the popular algorithms of a polyalphabetic cipher is Vigenere cipher. Vigenere cipher has been used for a long time, but this algorithm has weaknesses. The calculation of the encryption process is only involving additive cipher, it makes this algorithm vulnerability to attacker based on frequency analysis of the letter. The proposed method of this research is making Vigenere cipher more complex by combining monoalphabetic cipher and Vigenere cipher. One of the monoalphabetic ciphers is Affine cipher. Affine cipher has two steps in the encryption proce...
A Modified Version of Vigenere Cipher using 95×95 Table
International Journal of Engineering and Advanced Technology, 2020
Cryptography is a current field of research at the moment as it can be crucial to offer protection to extremely delicate and confidential records from criminal wrongdoings throughout transmission over the network. The vigenere cipher is one of the standard cryptographic algorithms that prevent attackers from understanding the raw data throughout the transmission. The traditional vigenere cipher encrypts only the alphabetic plaintext with a 26×26 vigenere table because it includes only 26 English alphabets A to Z. The researcher extended the original vigenere table into 95×95 which introduces all possible characters, mathematical symbols, digits, and punctuations that are available on an ordinary QWERTY keyboard layout that can be encrypted easily by this technique and conjointly introduced case sensitivity. The objective of this modification makes the cryptanalysis procedure more difficult and increases the information security.
The Effect Of Varying Key Length On A Vigenère Cipher
Vigenère cipher is one of the polyalphabetic substitution ciphers. Its weakness is the key repetition. To overcome this weakness there are many researchesgoing on to modify the key generation. In this paper a key generator function isimplemented with C++. Itgenerates a key with length depends on the message security level.This level is determined by the sender of the message, according to the security importance of the message. The security level determines the key length, which is a ratio from the plain-text message. This ratio varies from 10% to 100% from the plain-text length. This paper studies the effect of varying the key length on the performance of Vigenère cipher andits frequency analysis attack. When the key length increases the encryption and decryption time increases, the frequency analysis attack becomes more difficult and also the confusion is increased.
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.
An Extended Hybridization of Vigenere and Caesar Cipher Techniques for Secure Communication
Procedia Computer Science, 2016
Cryptography is one of the most popular fields of study these days as it is necessary to maintain the confidentiality of the data which is sent over the network. There are various cipher techniques available for encrypting the messages such as vernam cipher, mono-alphabetic cipher, poly-alphabetic cipher, etc. One of the most popular cipher techniques is the vigenere cipher. It is a poly-alphabetic cipher technique which uses the vigenere table for the process of encryption of alphabets. This paper extends the vigenere table by including numerical data, so that the numbers can also be encrypted using this technique. It combines the encryption process of vigenere and Caesar cipher for getting the cipher text from the given plaintext and key.
A HYBRID CRYPTOSYSTEM BASED ON VIGENERE CIPHER AND COLUMNAR TRANSPOSITION CIPHER
2013
Privacy is one of the key issues addressed by information Security. Through cryptographic encryption methods, one can prevent a third party from understanding transmitted raw data over unsecured channel during signal transmission. The cryptographic methods for enhancing the security of digital contents have gained high significance in the current era. Breach of security and misuse of confidential information that has been intercepted by unauthorized parties are key problems that information security tries to solve. This paper sets out to contribute to the general body of knowledge in the area of classical cryptography by developing a new hybrid way of encryption of plaintext. The cryptosystem performs its encryption by encrypting the plaintext using columnar transposition cipher and further using the ciphertext to encrypt the plaintext again using Vigenère cipher. At the end, cryptanalysis was performed on the ciphertext. The implementation will be done using java programming.
A Novel Encryption Approach Based on Vigenère Cipher for Secure Data Communication
Wirel. Pers. Commun., 2021
Nowadays, with the advancement of technologies in modern life communication and networks, the secrecy of a cryptographic technique has become a strong necessity. The Vernam’s cipher which is a specific form of Vigenere cipher is gaining attention of researchers in the cryptography. But the modern encryption methods based on matrices available in the literature have their limitations to utilize them. Therefore, motivated by numerous cryptographic techniques available in the literature, this study presents a novel encryption approach for secure data communication. The proposed encryption approach is based on Vigenere cipher in finite dimensional vector space. Furthermore, the proposed approach relies on an eternal decomposition which is indiscriminate in the key selection inside key space. To add complexity by text scrambling, a weird substitution cipher key is added to provide maximum derangement in the encrypted text structure. Additionally, in the lights of Shannon’s secrecy, a com...
Implementation of Vigenere Cipher as Cryptographic Algorithm in Securing Text Data Transmission
Innovare Academics Sciences Pvt. Ltd, 2020
Data theft is the process of stealing digital information from victims who do not know it in order to jeopardize privacy or o btain confidential information. Data theft becomes a problem for individual computer users, as well as large companies. Every individual has not covered the possibility of information theft because of someone's negligence. In safeguarding data, we need a technique that can help someone in keeping the data a secret. Data theft is unavoidable, but data security can be improved to preve nt data misuse. Vigenere algorithm, which is a cryptographic technique, can help secure data from data misuse. This algorithm works by shifti ng each character in the plaintext for the key provided. The key used can be a series of characters or are words that are difficult to guess by people who want to commit a crime. Implementing the Vigenere Cipher algorithm will guarantee data security.
A Complex Transformation of Monoalphabetic Cipher to Polyalphabetic Cipher: (Vigenère-Affine Cipher)
International Journal of Machine Learning and Computing
Fast progression of digital data exchange in electronic way, information security is becoming much more important in data storage and transmission on public communication networks. Cryptography has come up as a solution which plays a vital role in information security system against malicious attacks. In cryptography, there are various cipher techniques such as monoalphabetic cipher, polyalphabetic cipher, etc. to support data confidentiality as security mechanisms. They are methods of encrypting plain text message into cipher text protecting it from adversaries. The process of encryption of alphabets is the converting original message into non readable form. One of the most popular cipher techniques is the Vigenè re cipher. It is a polyalphabetic cipher technique which uses the Vigenè re table for the process of encryption of alphabets. As the Vigenè re cipher does not have the properties of diffusion and confusion, it is longer vulnerable to Kasiski and Friedman attacks based on letter frequency analysis. Thus, in this paper we propose a polyalphabetic cipher that is a new encryption and decryption technique with diffusion and confusion properties based on the concept of the complex cipher used by combining of Vigenè re cipher with Affine cipher for the increase of data security in data storage and transmission on public communication networks. Our proposed technique can also be considered as a complex transformation technique from Affine cipher known as a monoalphabetic cipher technique to a new polyalphabetic cipher technique that is called Vigenè re-Affine cipher.
A Cryptosystem Based On Vigenere Cipher By Using Mulitlevel Encryption Scheme
In today's world securing information in internet has become a crucial task. To secure such information, encryption plays an important role in information security. In this paper Vigenere cipher is considered which is to be most efficient and simplest one. Due to its repeating nature of the key it is vulnerable to attacks like Kasiski, known plain text etc., to find the length of encryption key. To overcome this, multi level encryption is done by using Vigenere cipher to improve better security against cryptanalysis.
DATA SECURITY USING VIGENERE CIPHER AND GOLDBACH CODES ALGORITHM
Vigenere chipper is one standard cryptographic algorithm, this algorithm very simple to use substitution as in Caesar cipher to encode the message text. One disadvantage of an extended vigenere key cipher which can determine by using a method, the method kasiski. in vigenere cipher, phrases 4/E: in the ciphertext generated from the encryption process so that the method kasiski can determine the encoded text. Goldbach codes algorithm is an algorithm for compression, which will be used to address the weaknesses in vigenere cipher. In this paper will try to discuss security with vigenere ciphertext, then ciphertext produced will be processed again using algorithms Goldbach codes. By applying the algorithm, Goldbach codes the result from the course of securing data using vigenere Chipper becomes harder to guess the original text despite using methods kasiski due to be acquired is the message of a different character.
Key Generation for Vigenere Ciphering Based on Genetic Algorithm
JOURNAL OF UNIVERSITY OF BABYLON for Pure and Applied Sciences
Cryptography is a science securing of information. Encryption requires impregnable keys to encrypt or decrypt data these keys should be unpredictable and not easily to break. In this research we use genetic algorithm to generate keys for vigenere cipher. The best key is used to perform encryption. The keys created by genetic algorithm are tested for randomness by using the entropy test. The entropy calculation shows that randomness of key generated based on genetic processing is better than chosen key in the classical vigenere cipher.
A Modified Vigenère Cipher based on Time and Biometrics features
Journal of Engineering
Biometrics is widely used with security systems nowadays; each biometric modality can be useful and has distinctive properties that provide uniqueness and ambiguity for security systems especially in communication and network technologies. This paper is about using biometric features of fingerprint, which is called (minutiae) to cipher a text message and ensure safe arrival of data at receiver end. The classical cryptosystems (Caesar, Vigenère, etc.) became obsolete methods for encryption because of the high-performance machines which focusing on repetition of the key in their attacks to break the cipher. Several Researchers of cryptography give efforts to modify and develop Vigenère cipher by enhancing its weaknesses. The proposed method uses local feature of fingerprint represented by minutiae positions to overcome the problem of repeated key to perform encryption and decryption of a text message, where, the message will be ciphered by a modified Vigenère method. Unlike the old us...
FPGA implementation of improved version of the Vigenere cipher
Indian Journal of Science and Technology, 2010
The use of cryptography has become increasingly important in recent years. Currently there are several good methods for encryption like AES and DES. Both of these algorithms require several rounds to encrypt a relatively small block of data. Stream ciphers, like Vigenere and Caesar in particular, only require one round. The Vigenere and Caesar ciphers, however, can be easily broken. Improved version of the Vigenere algorithm is obtained by adding random bits of padding to each byte to diffuse the language characteristics and this make the cipher unbreakable. In this paper we will present an efficient method for hardware implementation of the improved Vigenere algorithm.