Vigenere Cipher Research Articles

DNA-based cryptographic methods for data hiding in DNA media

Information security can be achieved using cryptography, steganography or a combination of them, where data is firstly encrypted using any of the available cryptography techniques and then hid into any hiding medium. Recently, the famous genomic DNA has been introduced as a hiding medium, known as DNA steganography, due to its notable ability to hide huge data sets with a high level of randomness and hence security. Despite the numerous cryptography techniques, to our knowledge only the vigenere cipher and the DNA-based playfair cipher have been combined with the DNA steganography, which keeps space for investigation of other techniques and coming up with new improvements. This paper presents a comprehensive analysis between the DNA-based playfair, vigenere, RSA and the AES ciphers, each combined with a DNA hiding technique. The conducted analysis reports the performance diversity of each combined technique in terms of security, speed, hiding capacity in addition to both key size and data size. Moreover, this paper proposes a modification of the current combined DNA-based playfair cipher technique, which makes it not only simple and fast but also provides a significantly higher hiding capacity and security. The conducted extensive experimental studies confirm such outstanding performance in comparison with all the discussed combined techniques.

Hybrid Methods of Cipher-text and RSA Cryptographic Algorithm Using Classical Vigenère

Maintaining the security of messages is a very important thing both within an organization and the personal especially in the age of information technology today. In order to the sent message does not fall into the one’s hands who are not interested, then encryption should be created to maintain the confidentiality of a message remains secure. Classical cryptography method using Vigenere Cipher and RSA (Riverst Shamir Adleman) is one of securing methods which will be used. In this case, the initial process is doing encryption on Vigenere cipher that produces a temporary ciphertext. The temporary ciphertext will be a plaintext on the RSA algorithm and then encrypted again to produce the actual ciphertext. Merging these two methods produces a ciphertext that is more powerful and difficult to solve.

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. General Terms Cryptography is the art and science of protecting information from unauthorized individuals. Encryption is a way of converting information (plaintext) into a form that is unreadable to unauthorized individuals (ciphertext).

Enhancing Security of Vignere Cipher using Modified RC4

Encryption is a way to enhance the security of a message or file by scrambling the contents so that it can be read only by someone who has the right encryption key to unscramble it. Encryption does not of itself prevent interception, but denies the message content to the interceptor. RC4 is one of the most popular encryption algorithms and finds its applications in many security protocols such as Wi-Fi Protocol Access (WPA) and Wired Equivalence Privacy (WEP). Although being a versatile encryption technique, RC4 faces numerous loopholes and weaknesses. Encrypted messages can sometimes be broken by cryptanalysis, also called codebreaking. It uses three secret keystwo secret keys K1 and K2 as seeds for Enhanced RC4 and K3 as the key for Vigenere Cipher substitution. It also uses two SBoxes S1 and S2. Both of them contain N elements from 0 to N-1. Although being a versatile encryption algorithm, Vigenere Cipher is not resistant to the Kasiski Attack. Through Cryptanalysis, one can determine the frequency of each letter and find a pattern in the Cipher text as well as the length of the key. In this paper, we propose an enhancement to the RC4 algorithm by converting it into a product cipher. Then we attempt encryption combining the 2 encryption techniques, Modified RC4 and Vigenere in a systematic manner. General Terms Cipher, Security, Stream Ciphers, Product Ciphers

An Extended Hybridization of Vigenere and Caesar Cipher Techniques for Secure Communication

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.

An enhanced approach on vigenere cipher by polyalphabetics

An enhanced approach on vigenere cipher by polyalphabetics

Merging of Vigenére Cipher with XTEA Block Cipher to Encryption Digital Documents

Security and confidentiality of documents or information has become a very important concern, in this modern era of computing speed increases dramatically, certainly considered threatening for some algorithms that are used to secure documents or information, it spawned an option to increase the security of documents by combining two cryptographic algorithms are Vigenere cipher with XTEA. Selection Vigenere cipher because it is not so vulnerable to solving method code is called frequency analysis, but some cryptanalyst has found security flaws of this algorithm, for it Vigenere cipher in this research carried out modifications to operations of mathematics, the results of these modifications will be combined with the algorithm-based XTEA block cipher, because his strength has been proven to secure the document (text). Based on the results of research conducted, the merger of the two algorithms are (VixTEA) can improve the security of ciphertext, it is measured by various indicators, namely, a visual comparison of encryption (frequency analysis), entropy value analysis, and analysis of bruteforce attacks. The results also showed that the VixTEA concept does not change the performance of the algorithm and the integrity of the digital documents can secured. General Terms Security.

New Approach in E-mail Based Text Steganography

In this study combination of lossless compression techniques and Vigenere cipher was used in text steganography that makes use of email addresses to be the keys to reconstruct the secret message which has been embedded into the email text. After selecting the cover text that has highest repetition pattern regarding to the secret message the distance matrix was formed. The members of distance matrix were compressed by following lossless compression algorithms as in written sequence; Run Length Encoding (RLE) + Burrows Wheeler Transform (BWT) + Move to Forward (MTF) + Run Length Encoding + Arithmetic Encoding (AE). Later on Latin Square was used to form stego key 1and then Vigenere table was used to increase complexity of extracting stego key 1. Final step was to choose e-mail addresses by using stego key 1 and stego key 2to embed secret message into forward e-mail platform. The experimental results showed that proposed method has reasonable performance with high complexity.

Security Analysis and Modification of Classical Encryption Scheme

Objectives: Computer security is all about the study of cyber attacks with a view to defend against them. Cryptography is considered to be a class of science by using the special art of transforming information in a protected way such that it can overcome the attacks. There is an immense requirement of strong cryptographic algorithms in order to withstand against the various attacks. Methods: The Kerchoff’’s Principle states that the encryption and decryption algorithms are always available to anyone. The security of the cipher against any sort of attack should be depends only on the secrecy of the key. There comes the play of cryptanalysis. It is art of breaking the keys by identifying the vulnerabilities existing in the systems. This paper deals with the classical encryption schemes and their cryptanalysis. The cryptanalysis for various encryption schemes differs a lot. Various cryptanalysis like statistical analysis, frequency analysis, trial and error (brute force) are carried out in this work. Findings: The classical encryption schemes such as caesar cipher, shift cipher, vigenere cipher, affine cipher and hill cipher are discussed in the paper. A detailed analysis about the security of the above mentioned ciphers are explored. Among the ciphers it is identified that if the key varies for each plaintext to be encrypted provides added security. But the worst is the management of the huge key space. A modified algorithm is proposed which can provide a better security using simple computations. In this approach lots of keys are used but generated from a single key by using simple shift and EXOR operation. In the main stream only one key need to be exchanged between the communication entities and for that exchange we can make use of the public key cryptosystem. Application: Cryptography is considered to be an ineluctable field in era of communication. Cryptographic algorithms acts as an underpinning for lots of applications such as Anonymous Remailers, Digital Signatures, Secured Money transactions etc.Keywords: Additive Cipher, Monoalphabetic Cipher, Multiplicative Cipher, Polyalphabetic Cipher

Cryptanalysis of Vigenere cipher using Cuckoo Search

Evolutionary techniques such as Genetic Algorithm (GA), Particle Swarm Optimization (PSO) and Cuckoo Search (CS) are promising nature-inspired meta-heuristic optimization algorithms. Cuckoo Search combined with Lévy flights behavior and Markov chain random walk can search global optimal solution very quickly. The aim of this paper is to investigate the applicability of Cuckoo Search algorithm in cryptanalysis of Vigenere cipher. It is shown that optimal solutions obtained by CS are better than the best solutions obtained by GA or PSO for the analysis of the Vigenere cipher. The results show that a Cuckoo Search based attack is very effective on the Vigenere cryptosystem.

Improving Security of Vigenère Cipher by Double Columnar Transposition

Protecting data from malicious attacks during storage and transmission is the reason for using encryption. Encryption can be achieved by two methods – Transposition and Substitution. Transposition refers to changing the order of characters in a given text. On the other hand, substitution is the process of replacing each character of the plaintext with some other character. Using a combination of transposition and substitution for encryption leads to greater security when compared to using either of them separately. Vigenere Cipher is a poly-alphabetic cipher. It is based on the substitution technique which uses multiple substitution alphabets. In this paper, we introduce double columnar transposition on Vigenere Cipher to enhance its security making cryptanalysis difficult.

Enhancing Security of Vigenere Cipher by Stream Cipher

Cryptography is a science of converting clear message into secret message nonreadable message, where message was encrypted at sender side then decrypted at receiver side. Vigenere is an example of substitution cipher, it has various limitations, in this paper we propose an advanced encryption algorithm which improves the security of Vigenere method by combining it with modern cipher method like Stream cipher, Stream cipher relatively regards as unbreakable method, and it uses binary form (instead of characters) where the Plaintext, Ciphertext and the Key are strings of bits. When applying the proposed algorithm, we see that the mentioned above combination cipher has a high degree of security, where cipher based on just Vigenere method is not secure. Also, the proposed algorithm makes the cryptanalysis, using frequency attack, more difficult. General Terms Information security, cryptography

Cryptanalysis of image scrambling based on chaotic sequences and Vigenère cipher

Recently, an image scrambling scheme based on chaos theory and Vigenere cipher was proposed. The scrambling process is firstly to shift each pixel by sorting a chaotic sequence as Vigenere cipher, and then the pixel positions are shuffled by sorting another chaotic sequence. In this study, we analyze the security weakness of this scheme. By applying the combination of chosen-plaintext attack and differential attack, we propose two efficient cryptanalysis methods. Results show that all the keystream can be revealed. The original image scrambling scheme can be remedied by leveraging the MD5 hash value of the plain image as the initial condition of the chaotic system.

Survey: Recent Modifications in Vigenere Cipher

In order to secure the information there are different polyalphabetic substitution ciphers are available. Out of these Vigenere cipher is considered to be most efficient and simplest one. Due to its repeating nature of the key it is also vulnerable to attacks. To overcome this, there are many researches going on to modify the conventional Vigenere Cipher. In this paper we have presented a review of recent modifications in Vigenere cipher and its cryptanalysis.

RDR Cube Cipher an Extension to Vigenere Cipher

Vigenere Cipher is an encrypting method of alphabetic text using different Shift ciphers or additive based on letter of keywords (1). It works on the set of 26 alphabets; however its scope is not just limited to English alphabets. Being an old method it's been vulnerable to many attacks. The proposed algorithm is to add a new dimension to this traditional method thus increasing its complexity and hence further reducing its vulnerability to different Vigenere Attacks. The keyword also called Encryption key used in Vigenere is used to select different table for encryption accordingly by the communicating parties using a modulus function. The more randomly the Table is varied based on the random selection of tables from a set of table virtually appearing like a cube more unpredictable the Encrypted text becomes hence increasing the complexity of the algorithm further. Different tables also reduces the variances of the characters hence making it more complex to analyze using the already existing Vigenere Analysis Algorithms.

Secured data transmission in a V-Blast encoded MIMO MCCDMA wireless communication system

In this paper, a comprehensive performance evaluative study has been made on a V-Blast encoded MIMO MCCDMA wireless communication system on encrypted synthetically generated binary data transmissionusing Minimum Mean Square Error (MMSE) and Zero- Forcing (ZF) Linear channel equalization schemes. The 4G compatible system deploys two channel encoding schemes (1/2-rated Convolutional and CRC) under BPSK, DPSK, QPSK and QAM digital modulations. In the present simulated system, synthetically generated binary data transmission has been secured with concatenated implementation of Vigenere Cipher and RSA cryptographic algorithm. It is anticipated from the numerical results that the BPSK modulation outperforms as compared to DPSK, QPSK and QAM modulation schemes in MMSE channel equalization and V-BLAST based 1/2-rated Convolutional channel Encoded MIMO MCCDMA schemes under AWGN channels. For ZF channel equalization and CRC channel coding, the system shows identical performance. For both cases, QPSK digital modulation shows worst performance. It is noticeable from the present study that the ZF with ½-rated Convolution coding scheme is superior as compared to MMSE with CRC coding scheme for BPSK digital modulation.

Image Encryption on Mobile Phone using Super Encryption Algorithm

Mobile phones have limited memory and computational resources. Modern encryption algorithms such as DES, AES, IDEA uses a complicated and complex algorithm, that are not suitable for image encryption on mobile phones. Necessary, it is tradeoff between speed, security, and flexibility. Problem to be investigated and resolved is how to get the image encryption algorithm which is simple yet safe, with the lightweight and efficient computing. The algorithm developed in this study was super-encryption algorithm that combines Playfair cipher and the Vigenere cipher. The experimental results show the cipher image histogram has a distribution of diversity and a significant difference to the plain image histogram, and frequency of occurrence of each intensity value in the histogram of cipher image is also uneven, which means can not provide clues to do statistical attack. The experimental results also showed a correlation between the elements of the image after encryption has decreased significantly. The average of quality encryption showed that the rate of change of image pixels is high enough so that cipher image difficult to identify. Tests on a cell phone showed that this algorithm requires only small computational resources. This shows that the algorithm is quite effective for image encryption on mobile phones.

Image scrambling based on chaotic sequences and Veginère cipher

Digital image scrambling is commonly used for image data security. This paper proposes an image scrambling algorithm based on chaos theory and Vigenere cipher. The scrambling process is performed on the grey level of each pixel by sorting the chaotic sequence as Vigenere cipher, then the pixel positions are shuffled by accompanied chaotic sequence. The new scheme avoid discretization of chaotic sequence, therefore there is no requirement of probability density function of the chaotic orbits. The simulation and experiments validate the effectiveness and efficiency of the proposed new algorithm.

Secure text message transmission in a 4G compatible MIMO MCCDMA system with combined implementation of Vigenere Cipher and RSA cryptographic algorithm

In this paper, a comprehensive performance evaluative study has been made on a secured MIMO MCCDMA wireless communication system with implementation of Minimum Mean Square Error (MMSE) and Zero- Forcing (ZF) Linear channel equalization schemes. The 4G compatible system deploys two channel encoding schemes(1/2-rated Convolutional and CRC ) under BPSK,DPSK QPSK and QAM digital modulations. In the present simulated system, a text message transmission has been secured with concatenated implementation of Vigenere Cipher and RSA cryptographic algorithm. It is anticipated from the numerical results that with MMSE channel equalization and 1/2-rated Convolutional channel Encoding schemes, the MIMO MCCDMA system outperforms in BPSK digital modulation under AWGN and Raleigh fading channels. In CRC channel coding, the system shows comparatively worst performance in higher Signal to Noise ratio(SNR) values under DPSK, QPSK and QAM digital modulations. It has been observed from the present study that the system performance deteriorates with increase in noise power as compared to signal power .

Alpha-Qwerty Cipher: An Extended Vigenere Cipher

The Vigenere Cipher is a traditional method which involves encrypting alphabetic text by using a series of different Caesar Ciphers based on the letters of a keyword. The Vigenere Cipher works on the set of 26 English alphabets. In this paper we introduce the Alpha-Qwerty Cipher and reverse Alpha-Qwerty Ciphers which are the extensions to the Vigenere Cipher. This cipher works on a set of 92 characters by introducing case sensitivity and by adding digits and some other symbols to the existing Vigenere Cipher which is of 26 characters. This paper also modifies the mapping sequence from the plain text to the cipher text.