Substitution Cipher Research Articles

Manuscrito de Voynich - Análisis del algoritmo de codificación con los métodos de cifrado conocidos en la época medieval y resultados de las marginalias que no fueron encriptadas

En el presente estudio describo y analizo dos objetivos, el primero es sobre la oposición y la equivalencia del algoritmo de codificación del manuscrito Voynich con los métodos conocidos de cifrado del período medieval. Según los resultados de mi investigación innovadora del manuscrito Voynich, este fue escrito en gallego medieval (gallego-portugués). Su algoritmo de codificación fue influenciado por el cifrado de sustitución del uso de un cifrado polialfabético para la mayor parte de su texto, así como definitivamente fue influenciado por el cifrado de transposición para texto alquímico de cifrado doble. Sin embargo, debe mencionarse que existen diferencias significativas entre los códigos que se usaron en el período medieval y el algoritmo codificado del manuscrito Voynich. Por la razón que hizo que el descifrado fuera más complicado a lo largo de los siglos, el cifrado por sustitución de un cifrado polialfabético se usó en parte y simultáneamente con cifrado monoalfabético, además del texto sin codificar. Por lo tanto, lo principal a tener en cuenta es que el segundo objetivo de mayor interés en este artículo en particular son partes de los textos del manuscrito de Voynich –marginalias– que no se cifraron en absoluto y su lectura.

Dickens and the Stenographic Mind by Hugo Bowles

Reviewed by: Dickens and the Stenographic Mind by Hugo Bowles Lillian Nayder (bio) Hugo Bowles. Dickens and the Stenographic Mind. Oxford UP, 2019. Pp. xviii + 193. $74. ISBN 978-0-19-882907-2. In June 1858, Dickens corresponded with Francis Waugh, a young admirer, signing his letter to the boy in a characteristic way, by underscoring his signature with a sequence of diminishing lines penned from a single stroke–in this particular instance, seven switchbacks in bright blue ink. Dickens's flourish reveals his embrace of the superfluous–so his postscript to Waugh suggests: "Perhaps you'll wonder why I make that flourish. I don't know. I have not the least idea" (Letters 8: 593). As Daniel Tyler notes in his introduction to Dickens's Style (2013), the novelist seems to revel in what is unnecessary and excessive, his language taking on "a life of its own" as it "runs away with itself under its own impulses" (9). Or as George Orwell expressed the point in 1939, "the outstanding, unmistakable mark of Dickens's writing is the unnecessary detail" (qtd. Tyler 7). In Dickens and the Stenographic Mind, Hugo Bowles presents us with a very different side of Dickens–the writer trained to elide and compress–as he worked "as a legal, parliamentary, and news reporter … between 1829 and 1834" (17). Far from reveling in excess, Dickens the shorthand writer was forced to capture speech economically, his stenographic art one in which "you … write more with less" (3). Following Thomas Gurney's principles as outlined in Brachygraphy or An Easy and Compendious System of Shorthand (his copy most likely the fifteenth edition, published in 1825), Dickens "squeeze[d] redundancy out of the writing system" (13). He did so, in part, by omitting vowels from words and using a code of symbols to represent alphabetic letters, which are themselves a code of speech sounds (20). As Bowles explains, shorthand is "a substitution cipher," with "plaintext" replaced by "ciphertext" (21). The Gurney system provided symbols for each letter (or paired letters) of the alphabet–with each symbol also representing a specific word or set of words, most of them beginning with that alphabetical letter and "constructed around just four types of shape (dot, dash, curve, line), with the occasional small circle" (28). In addition, one set of arbitrary characters stood for "prepositions and terminations" and another for particular keywords or sets of keywords–in the second set, "g" for "govern," "governing," and "government," to cite one example (25). The writer abbreviated words before transcribing them into shorthand, [End Page 285] generally dropping vowels unless they occurred at the start of words–for instance, "assault … to <aslt>" (22). Gurney was particularly difficult not only because some letters shared a symbol, because certain features of vowel coding were left to the discretion of the shorthand writer, and because consonant sounds can be spelt by more than one letter, leading to inconsistencies in representation–but also and more importantly because the system was based on spelling rather than pronunciation–on "letters rather than sounds" (24). Unlike Pitman, therefore, Gurney required two phases of encoding, as spoken words heard in court or in parliament were first changed into written words in the mind of the shorthand writer, and then into the stenographic code. Despite the system's many difficulties, Dickens mastered it as a teenager, and Bowles explores the consequences of the writer's "acquired stenographic competence, the 'stenographic mind'" (4); he examines in considerable detail what Dickens learned from Gurney's system–the "experimentation" with language and syntax that it promoted (42)–and explains how the novelist made it his own, "personalizing" it "for the purposes of his own shorthand," altering the shapes of symbols and inventing his own arbitrary characters (40–41, 44–45)–and thus rendering some of his extant shorthand manuscripts virtually undecipherable to this day. Detailing the complexities of the stenographic process, Bowles underscores that it required both compression and expansion, as the stenographic writer faced the challenge of "translating" his own shorthand manuscripts into longhand–a process that required the writer, as shorthand reader, to play with language as he considered the linguistic variations and possibilities created by reinserting...

An Efficient IoT-Based Patient Monitoring and Heart Disease Prediction System Using Deep Learning Modified Neural Network

The leading causes of death worldwide are chronic illnesses suchlike diabetes, Heart Disease (HD), cancer as well as chronic respiratory malady. It is remarkably intricate to diagnose HD with disparate symptoms or features. With the augmentation in popularity of smart wearable gadgets, a chance to render an Internet of Things (IoT) solution has turned out to be more. Unfortunately, the survival rates are low for the people suffering from sudden heart attacks. Consequently, a patient monitoring scheme intended for heart patients utilizing IoT centered Deep Learning Modified Neural Network (DLMNN) is proposed to assist in the HD diagnosis, and medication is given accordingly. This proposed technique is executed via `3' steps: I) Authentication, ii) Encryption, and iii) Classification. First, by utilizing the substitution cipher (SC) together with the SHA-512, the heart patient of the specific hospital is authenticated. Subsequently, the wearable IoT sensor device, which is fixed to the patient's body, concurrently transmits the sensor data to the cloud. This sensor data is encrypted and securely transmitted to the cloud utilizing the PDH-AES technique. After that, the encrypted data is finally decrypted, and by employing the DLMNN classifier, the classification is done. The classified outcomes comprise `2'types of data: i) normal and ii) abnormal. It denotes the patient's heart condition and if the outcome is abnormal, an alert text is passed to the physician for treating the patient. The investigational outcomes are estimated and the DLMNN for HD diagnosis shows improvement as compared to existing algorithms. Additionally, the proposed PDH-AES used in support of secure data transmission results in the highest level of security i.e. 95.87%, and it is achieved in the lowest time for encryption along with decryption when weighted against the existent AES.

Slippery hill-climbing technique for ciphertext-only cryptanalysis of periodic polyalphabetic substitution ciphers

We present a stochastic method for breaking general periodic polyalphabetic substitution ciphers using only the ciphertext and without using any additional constraints that might come from the cipher’s structure. The method employs a hill-climbing algorithm for individual key alphabets, with occasional slipping down the hill. We implement the method with a computer and achieve reliable results for a sufficiently long ciphertext (150 characters per key alphabet). Because no constraints among the key alphabets are used, this method applies to any periodic polyalphabetic substitution cipher.

Enhanced Substitution Cipher Technique for Image Encryption

Now a days, Information Security plays an important role in this modern world. With the global usage of the Internet, virtually world is interconnected to each other, while it has created a lot of risks to the users who are involved in it. The users, businesses and organizations worldwide are suffering from a continuousproblems from attackers and hackers, who have a variety of tools and techniques in order to break the secret information and make changes to the data, which leads to security issues. One of the most important aspect is transmission of message such as text, image over the network securely. Many cryptographic algorithms have been proposed for secured transmission so that no other person can gain the access of transmitted data. The Encryption algorithm plays an important role to transmit data through the network. In this paper, an image data is considered, generally each and every pixel is encoded with a secret key and transmitted and decrypted at the receiver side. In some algorithms, the blocks of pixels are encoded with differentkeys. In this paper a new methodology introduced to perform the encryption with some variation in substitution cipher algorithm on split sub matrices with different keys instead of sequence block of pixels. By applying this methodology, it increases the security a lot for the information and can be easily transmitted in the network.

Various Ciphers in Classical Cryptography

Data Encryption is often widely used tool to provide security features. It translates the clear text into code such that it can only be accessed with the person who has the appropriate key. The recovery of clear text from such an unscrambled data is deciphering. Enciphering can be implemented by using some substitution technique, shifting technique or even mathematical logics. Application of such types of techniques is difficult to retrieve clear text. In the bygone times, several symmetric key base algorithms have been developed. This paper enlightens and analyzes the substitution ciphers and transposition ciphers. With the comparison of different parameters used in the algorithms give significance of the algorithm.

An Improved Genetic Algorithm and A New Discrete Cuckoo Algorithm for Solving the Classical Substitution Cipher

Searching secret key of classical ciphers in the keyspace is a challenging NP-complete problem that can be successfully solved using metaheuristic techniques. This article proposes two metaheuristic techniques: improved genetic algorithm (IGA) and a new discrete cuckoo search (CS) algorithm for solving a classical substitution cipher. The efficiency and effectiveness of the proposed techniques are compared to the existing tabu search (TS) and genetic algorithm (GA) techniques using three criteria: (a) average number of key elements correctly detected, (b) average number of keys examined before determining the required key, and (c) the mean performance time. As per the results obtained, the improved GA is comparatively better than the existing GA for criteria (a) and (c), while the proposed CS strategy is significantly better than rest of the algorithms (i.e., GA, IGA, and TS) for all three criteria. The obtained results indicate that the proposed CS technique can be an efficient and effective option for solving other similar NP-complete combinatorial problems also.

BLOCK SYMMETRIC CIPHER WITH RANDOM S-BOXES

This paper describes a new 256-bit block symmetric substitution-permutation cipher, called managed substitution cipher. This is a cipher with single-layer permutated transformations in each cycle. The management of substituted transformations occur by including them in a chain so that the output value of the previous SL transform is fed to the input of the current fortified 32-bit substituted transformation (SL conversion) along with the current value of the input data block through the adder for modulo 2. This enables to activate almost all S-blocks of the second cycle and subsequent cycles and eventually improve the dynamic indicators of the arrival of the cipher to the state of random substitution. The results of the evaluation of randomness indicators and the possibility of using random S-blocks are given. It is shown that such construction of cycled function allows us to use random substitutions without any selection in a cipher without reducing its strength.

Automated cryptanalysis of substitution cipher using Hill climbing with well designed heuristic function

Automated cryptanalysis of substitution cipher using Hill climbing with well designed heuristic function

Analysis of Four Historical Ciphers Against Known Plaintext Frequency Statistical Attack

The need of keeping information securely began thousands of years. The practice to keep the information securely is by scrambling the message into unreadable form namely ciphertext. This process is called encryption. Decryption is the reverse process of encryption. For the past, historical ciphers are used to perform encryption and decryption process. For example, the common historical ciphers are Hill cipher, Playfair cipher, Random Substitution cipher and Vigenere cipher. This research is carried out to examine and to analyse the security level of these four historical ciphers by using known plaintext frequency statistical attack. The result had shown that Playfair cipher and Hill cipher have better security compare with Vigenere cipher and Random Substitution cipher.

Cracking the code of the Rohonc Codex

ABSTRACTThe Rohonc Codex is a small 448-page codex handwritten in a script that has resisted deciphering since the codex was discovered in 1839. The main cause of this failure may be the fact, as we reveal, that the writing is not a substitution cipher (or “ancient alphabet”) as most researchers presupposed but is in fact a code system with features that no codebreaker would expect, the breaking of which is an extremely heuristic task. This article is intended to be the first of three or four in which we summarize our findings made during our years-long research of the Rohonc Codex. In the present article we discuss general features of the text, our methodological criteria, and the story of cracking the code. To give weight to our argument we present several interlinear translations of passages from the codex’s text. This will be expanded by further articles in which we plan to describe some advanced features of the code such as its morphology, syntax, and peculiarities, as well as the possible language(s) of the author; we will also provide a detailed table of contents, further indices, and a glossary.

Cryptanalysis on classical cipher based on Indonesian language

Cryptanalysis is a process of breaking a cipher in an illegal decryption. This paper discusses about encryption some classic cryptography, breaking substitution cipher and stream cipher, and increasing its security. Encryption and ciphering based on Indonesian Language text. Microsoft Word and Microsoft Excel were chosen as ciphering and breaking tools.

A Study of Caesar Cipher and Transposition Cipher in Jawi Messages

Cryptography known as art and science which is used to hide the messages that contain a few policy terminologies. These terminologies in cryptography are plaintext/ messages, ciphertext, encryption, decryption and key. Encryption is a proses to transform the plaintext together with key into ciphertext. Decryption is the reverse process of encryption. Caesar cipher and transposition cipher are two historical ciphers in cryptography. Caesar cipher is a monoalphabetic cipher. It is a substitution cipher which replace each letter in plaintext with another letter to form the ciphertext. Transposition cipher uses a technique which rearrangement letters in plaintext with a keyword and produce the ciphertext. Caesar cipher and Tansposition cipher both are commonly used to encrypt the English letters. The output of encrypted of English letters are known as ciphertext. The attacker can easily cryptanalysed the Caesar cipher by observing the frequency distribution English letters and ciphertext. For Transposition cipher, the cipher can be cracked by knowing the keyword. To date, there is no any research encrypt Jawi letters using Caesar cipher and Transposition cipher. Hence, in this paper encryption and decryption by using Caesar cipher and Transposition cipher in Jawi messages are proposed. Next, the security level of Caesar cipher and Transposition cipher in Jawi messages are compared. The result has shown that both ciphers are still not secure to protect the confidentiality of the Jawi messages.

TRANSPOLY HILL CIPHER — AN IMPROVEMENT OVER TRADITIONAL HILL CIPHER

Every encryption technique is based on any one of two facts- substitution or transposition. Sometimes the combination of both techniques is used. A substitution technique is one in which the letters of plaintext are replaced by other letters or by numbers or symbols. The basic concept behind this paper is to improve the strength of Hill cipher, ‘a multiple-letter substitution cipher’ against known plaintext attack. This paper presents a modified approach which is an enhancement over traditional Hill cipher by using symmetric matrix of plaintext letters.

Cryptanalysis of Mono-Alphabetic Substitution Ciphers using Genetic Algorithms and Simulated Annealing

In this paper, we intend to apply the principles of genetic algorithms along with simulated annealing to cryptanalyze a mono-alphabetic substitution cipher. The type of attack used for cryptanalysis is a ciphertext-only attack in which we don’t know any plaintext. In genetic algorithms and simulated annealing, for ciphertext-only attack, we need to have the solution space or any method to match the decrypted text to the language text. However, the challenge is to implement the project while maintaining computational efficiency and a high degree of security. We carry out three attacks, the first of which uses genetic algorithms alone, the second which uses simulated annealing alone and the third which uses a combination of genetic algorithms and simulated annealing.

Penerapan Metode End Of File Pada Steganografi Citra Gambar dengan Memanfaatkan Algoritma Affine Cipher sebagai Keamanan Pesan

The development of the world of information technology is very fast lately influential in all aspects of life. Kriprografi is a science based on mathematical techniques to deal with information security such as confidentiality, data integrity, and entity authentication. Affine Cipher or Affine password is a substitution cipher that is specifically for encryption or decryption per character. Therefore, Affine's password includes the stream cipher cryptographic algorithm. Steganography is a way of hiding the contents of a data in a cover of media or other digital data that cannot be predicted by ordinary people so as not to arouse suspicion from those who see it. The steganography image file has the same number of pixels as the original image file and there is no color difference between the two. The size of the steganography image file will increase, according to the length of the hidden message plus 6 bytes, in the form of 1 byte EOF and 5 byte message length. The End Of File (EOF) method is a technique for inserting data at the end of a file. When opened with a photo editor application, both images have the same pixel size, namely 240 x 238, and do not change color. In this test, what changes is the size of the image file, ie the initial size of the image is 49.132 bytes, changes to 49.145 bytes, or there is an addition of 13 bytes

An automatic cryptanalysis of simple substitution ciphers using compression

ABSTRACTAutomatic recognition of correct solutions as a result of a ciphertext only attack of simple ciphers is not a trivial issue and still remains a taxing problem. A new compression based method for the automatic cryptanalysis of simple substitution ciphers is introduced in this paper. In particular, this paper presents how a Prediction by Partial Matching (PPM) text compression scheme, a method that shows a high level of performance when applied to different natural language processing tasks, can also be used for the automatic decryption of simple substitution ciphers. Experimental results showed that approximately 92% of the cryptograms were decrypted correctly without any errors and 100% with just three errors or less. Extensive investigations are described in this paper, in order to determine which is the most appropriate type of PPM scheme that can be applied to the problem of automatically breaking substitution ciphers. This paper shows how a new character-based PPM variant significantly outperforms other schemes including the standard Gzip and Bzip2 compression schemes. We also apply a word-based variant which when combined with the character-based method leads to further improved results.

Application of Genetic Algorithm in Cryptanalysis of Mono-alphabetic Substitution Cipher

Application of Genetic Algorithm in Cryptanalysis of Mono-alphabetic Substitution Cipher

Vigenère scores for malware detection

Previous research has applied classic cryptanalytic techniques to the malware detection problem. Specifically, scores that are based on simple substitution cipher cryptanalysis have been considered. In this research, we analyze two malware scoring techniques based on the classic Vigenere cipher. Our first approach relies only on the index of coincidence (IC), which is used for example, to determine the length of the keyword in a Vigenere ciphertext. To compute the IC, we consider both the Kasisky Test and Friedman’s Test. We also consider a score based on a more complete cryptanalysis of a Vigenere cipher, where the IC calculation is the first step. We find that both of these scores outperform comparable malware scores in selected cases.

Improved Markov Chain Monte Carlo method for cryptanalysis substitution-transposition cipher

In this paper we first investigate the use of Markov Chain Monte Carlo (MCMC) methods to attack classical ciphers. MCMC has previously been used to break simple substitution, transposition and substitution-transposition ciphers. Here, we improve the accuracy of obtained results by these algorithms and we show the performance of the algorithms using quasi random numbers such as Faure, Sobol and Niederreiter sequences.