Caesar Cipher Caesar Cipher the Action of a Caesar Cipher Is To
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Simple Substitution and Caesar Ciphers
Spring 2015 Chris Christensen MAT/CSC 483 Simple Substitution Ciphers The art of writing secret messages – intelligible to those who are in possession of the key and unintelligible to all others – has been studied for centuries. The usefulness of such messages, especially in time of war, is obvious; on the other hand, their solution may be a matter of great importance to those from whom the key is concealed. But the romance connected with the subject, the not uncommon desire to discover a secret, and the implied challenge to the ingenuity of all from who it is hidden have attracted to the subject the attention of many to whom its utility is a matter of indifference. Abraham Sinkov In Mathematical Recreations & Essays By W.W. Rouse Ball and H.S.M. Coxeter, c. 1938 We begin our study of cryptology from the romantic point of view – the point of view of someone who has the “not uncommon desire to discover a secret” and someone who takes up the “implied challenged to the ingenuity” that is tossed down by secret writing. We begin with one of the most common classical ciphers: simple substitution. A simple substitution cipher is a method of concealment that replaces each letter of a plaintext message with another letter. Here is the key to a simple substitution cipher: Plaintext letters: abcdefghijklmnopqrstuvwxyz Ciphertext letters: EKMFLGDQVZNTOWYHXUSPAIBRCJ The key gives the correspondence between a plaintext letter and its replacement ciphertext letter. (It is traditional to use small letters for plaintext and capital letters, or small capital letters, for ciphertext. We will not use small capital letters for ciphertext so that plaintext and ciphertext letters will line up vertically.) Using this key, every plaintext letter a would be replaced by ciphertext E, every plaintext letter e by L, etc. -
Cryptography in Modern World
Cryptography in Modern World Julius O. Olwenyi, Aby Tino Thomas, Ayad Barsoum* St. Mary’s University, San Antonio, TX (USA) Emails: [email protected], [email protected], [email protected] Abstract — Cryptography and Encryption have been where a letter in plaintext is simply shifted 3 places down used for secure communication. In the modern world, the alphabet [4,5]. cryptography is a very important tool for protecting information in computer systems. With the invention ABCDEFGHIJKLMNOPQRSTUVWXYZ of the World Wide Web or Internet, computer systems are highly interconnected and accessible from DEFGHIJKLMNOPQRSTUVWXYZABC any part of the world. As more systems get interconnected, more threat actors try to gain access The ciphertext of the plaintext “CRYPTOGRAPHY” will to critical information stored on the network. It is the be “FUBSWRJUASLB” in a Caesar cipher. responsibility of data owners or organizations to keep More recent derivative of Caesar cipher is Rot13 this data securely and encryption is the main tool used which shifts 13 places down the alphabet instead of 3. to secure information. In this paper, we will focus on Rot13 was not all about data protection but it was used on different techniques and its modern application of online forums where members could share inappropriate cryptography. language or nasty jokes without necessarily being Keywords: Cryptography, Encryption, Decryption, Data offensive as it will take those interested in those “jokes’ security, Hybrid Encryption to shift characters 13 spaces to read the message and if not interested you do not need to go through the hassle of converting the cipher. I. INTRODUCTION In the 16th century, the French cryptographer Back in the days, cryptography was not all about Blaise de Vigenere [4,5], developed the first hiding messages or secret communication, but in ancient polyalphabetic substitution basically based on Caesar Egypt, where it began; it was carved into the walls of cipher, but more difficult to crack the cipher text. -
ILLUSTRATED from the in the NEWBERRY LIBRARY By
4° S 5999)-Zz YZANflNE ELEHEffS IN HUMANISTIC SC1W1 ILLUSTRATED FROM THE AYLVS GELL}vS OF.1445' IN THE NEWBERRY LIBRARY By STANLEY MORI SON Fellow of the Newberry Library CHICAGO, I LLI NOI S Written, Composed and Printed at THE NEWBERRY LIBRARY 1952 S, F trncnl. t , /'t".t pMit., e554' c emn,., fänl- ýr rt, i,! ra, e, 'r'u ret, r lnbl. trl: t , ielirrt , N on tluer cýj"qni uänerro inc. týn, »int' lembnm Ä ý i! em, li, b, g, r. li brich-L4 ti+rre' rrmif, C. trcý:, llarrn in pr. ccef+l'prm, o r:, rr luea, l : ., tsm . AVLýGELý. If NocrvM ATTICARVM CiBL-R,. ". r" ... EýtµIVSc: }CPtýC. trceP. Xf. FELFc-t1%"Rý., ýo ortýert[ uoutbuli" rrr7. c"' iatLt:c: des: e; t mttlr, cluF' %up, wrpdLtntr, dcý; etitf nomtiulr, dc' rta trionc ,u lege 4's: 'ucrf+: C p:tcrrm. t, stý+c:! .mtccinsm! mn1rA .r ansnmt. t citcs (ýolir.t ('rnr. cArttttlttrn ý, - , in IAfVS hyraniil'qnAs orsnonc gr-,ec. t drrrbK! compoille: r. 4ý. rn: i :, rrr 'ppr.:: l7crrn. tiý . "nquininb: rcrirrri t»arirm trr {tali: ran, tsri cicýýco noc. ibnlo .+ý, pc1L 1 tan, ! 'crip! 'cýYrnr, clm boiic(gr. cc.t ucceri' lrý1Zu. t lr. tlot'itocýcýnýfunr; clclorci171 i11 [r+ncai: {zifi. i rr, agsli copi. i Fucýeir; ýýt 1i2 ca tm: t o, pi p1tctg: foltrA liT1t cotrlpLitrsttt. t. Goief t: ttY st-trim; ob ctndcln c.irn ro[Tstmuf jP tr.ylt. t tttnc ter. ttittettro/i(r&'tn. t. mnlr. lntci: tppol. tr (üpretttA "`1. litliiittLlt1, rs1 ltitQti[oýdtcs ditArnirt otttitm trtgsit t. -
Cryptanalysis of Mono-Alphabetic Substitution Ciphers Using Genetic Algorithms and Simulated Annealing Shalini Jain Marathwada Institute of Technology, Dr
Vol. 08 No. 01 2018 p-ISSN 2202-2821 e-ISSN 1839-6518 (Australian ISSN Agency) 82800801201801 Cryptanalysis of Mono-Alphabetic Substitution Ciphers using Genetic Algorithms and Simulated Annealing Shalini Jain Marathwada Institute of Technology, Dr. Babasaheb Ambedkar Marathwada University, India Nalin Chhibber University of Waterloo, Ontario, Canada Sweta Kandi Marathwada Institute of Technology, Dr. Babasaheb Ambedkar Marathwada University, India ABSTRACT – 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. Key words: Cryptanalysis, mono-alphabetic substitution cipher, genetic algorithms, simulated annealing, fitness I. Introduction II. Mono-alphabetic substitution cipher Cryptanalysis involves the dissection of computer systems by A mono-alphabetic substitution cipher is a class of substitution unauthorized persons in order to gain knowledge about the ciphers in which the same letters of the plaintext are replaced unknown aspects of the system. It can be used to gain control by the same letters of the ciphertext. -
The Mathemathics of Secrets.Pdf
THE MATHEMATICS OF SECRETS THE MATHEMATICS OF SECRETS CRYPTOGRAPHY FROM CAESAR CIPHERS TO DIGITAL ENCRYPTION JOSHUA HOLDEN PRINCETON UNIVERSITY PRESS PRINCETON AND OXFORD Copyright c 2017 by Princeton University Press Published by Princeton University Press, 41 William Street, Princeton, New Jersey 08540 In the United Kingdom: Princeton University Press, 6 Oxford Street, Woodstock, Oxfordshire OX20 1TR press.princeton.edu Jacket image courtesy of Shutterstock; design by Lorraine Betz Doneker All Rights Reserved Library of Congress Cataloging-in-Publication Data Names: Holden, Joshua, 1970– author. Title: The mathematics of secrets : cryptography from Caesar ciphers to digital encryption / Joshua Holden. Description: Princeton : Princeton University Press, [2017] | Includes bibliographical references and index. Identifiers: LCCN 2016014840 | ISBN 9780691141756 (hardcover : alk. paper) Subjects: LCSH: Cryptography—Mathematics. | Ciphers. | Computer security. Classification: LCC Z103 .H664 2017 | DDC 005.8/2—dc23 LC record available at https://lccn.loc.gov/2016014840 British Library Cataloging-in-Publication Data is available This book has been composed in Linux Libertine Printed on acid-free paper. ∞ Printed in the United States of America 13579108642 To Lana and Richard for their love and support CONTENTS Preface xi Acknowledgments xiii Introduction to Ciphers and Substitution 1 1.1 Alice and Bob and Carl and Julius: Terminology and Caesar Cipher 1 1.2 The Key to the Matter: Generalizing the Caesar Cipher 4 1.3 Multiplicative Ciphers 6 -
Ancient Authors 297
T Ancient authors 297 is unknown. His Attic Nights is a speeches for the law courts, collection of essays on a variety political speeches, philosophical ANCIENT AUTHORS of topics, based on his reading of essays, and personal letters to Apicius: (fourth century AD) is the Greek and Roman writers and the friends and family. name traditionally given to the lectures and conversations he had Columella: Lucius Iunius author of a collection of recipes, heard. The title Attic Nights refers Moderatus Columella (wrote c.AD de Re Coquinaria (On the Art of to Attica, the district in Greece 60–65) was born at Gades (modern Cooking). Marcus Gavius Apicius around Athens, where Gellius was Cadiz) in Spain and served in the was a gourmet who lived in the living when he wrote the book. Roman army in Syria. He wrote a early first centuryAD and wrote Cassius Dio (also Dio Cassius): treatise on farming, de Re Rustica about sauces. Seneca says that he Cassius Dio Cocceianus (c.AD (On Farming). claimed to have created a scientia 150–235) was born in Bithynia. He popīnae (snack bar cuisine). Diodorus Siculus: Diodorus had a political career as a consul (wrote c.60–30 BC) was a Greek Appian: Appianos (late first in Rome and governor of the from Sicily who wrote a history of century AD–AD 160s) was born in provinces of Africa and Dalmatia. the world centered on Rome, from Alexandria, in Egypt, and practiced His history of Rome, written in legendary beginnings to 54 BC. as a lawyer in Rome. -
Herodian History of the Roman Empire Source 2: Aulus Gellius Attic
insulae: how the masses lived Fires Romans Romans in f cus One of the greatest risks of living in the densely populated city of Rome, and particularly in insulae was that of fires. Fires broke out easily (due to people cooking on open flames), spread easily (due to buildings being constructed out of wood, and buildings being built so closely together) and were hard to control. Several times large parts of the city went up in flames. It was not unusual for imperial funds to make good losses of impoverished wealthy citizens in the wake of a fire. Source 1: Herodian History of the Roman Empire In this passage from Herodian riots have broken out in the city of Rome, and soldiers combatting civilians started setting fire to houses. The soldiers did, however, set fire to houses that had wooden balconies (and there were many of this type in the city). Because a great number of houses were made chiefly of wood, the fire spread very rapidly and without a break throughout most of the city. Many men who lost their vast and magnificent properties, valuable for the large incomes they produced and for their expensive decorations, were reduced from wealth to poverty. A great many people died in the fire, unable to escape because the exits had been blocked by the flames. All the property of the wealthy was looted when the criminal and worthless elements in the city joined with the soldiers in plundering. And the part of Rome destroyed by fire was greater in extent than the largest intact city in the empire. -
Architectural Encounters Between Idea and Material the 1547 Frontispiece of Walther Hermann Ryff
ARCHITECTURAL ENCOUNTERS 179 Architectural Encounters between Idea and Material The 1547 Frontispiece of Walther Hermann Ryff PAUL EMMONS Virginia Tech The renaissance frontispiece is simultaneously an that presented through a combination of word and encounter between reader and author and inhabit- image the idea of its content^.^ Frontispieces thus ant and building. The idea of the book is personified are excellent visual sources to study the significance into an architectural image. Reader and author are of a text. Architects often drew frontispieces, not face-to-face even though the later is absent and the only for their own books, but also for many other book stands as a physical incarnation of the ideas subjects. The visual threshold of frontispiece for of the author. This paper will examine one notable renaissance architectural treatises was variously renaissance architectural frontispiece in Walther shown as an altar (Palladio), triumphal arch (Bar- Hermann Ryff's Architectur (1547) to reconsider the baro), curtain or veil (Bartoli), window (Vignola), relation between idea and material in architectural or pedimented entry (Scamozzi). theory and practice today. Frontispieces employed allegorical illustrations like The illustrated architectural frontispiece developed emblems. Emblems originated with the renaissance with the early printed book.' At this time, printers humanist attempt to create a modern equivalent only produced the pages and sold them tied in a to Egyptian hieroglyphs. With the rediscovery of bundle which was then taken to a separate leather Horapollo's Hieyroglyphica in the fifteenth century, worker for the book's cover. The cover represented it was thought that the esoteric picture language of the owner while the first page, the frontispiece, the Egyptians could be deciphered and numerous represented the interior of the book. -
A Hybrid Cryptosystem Based on Vigenère Cipher and Columnar Transposition Cipher
International Journal of Advanced Technology & Engineering Research (IJATER) www.ijater.com A HYBRID CRYPTOSYSTEM BASED ON VIGENÈRE CIPHER AND COLUMNAR TRANSPOSITION CIPHER Quist-Aphetsi Kester, MIEEE, Lecturer Faculty of Informatics, Ghana Technology University College, PMB 100 Accra North, Ghana Phone Contact +233 209822141 Email: [email protected] / [email protected] graphy that use the same cryptographic keys for both en- Abstract cryption of plaintext and decryption of cipher text. The keys may be identical or there may be a simple transformation to Privacy is one of the key issues addressed by information go between the two keys. The keys, in practice, represent a Security. Through cryptographic encryption methods, one shared secret between two or more parties that can be used can prevent a third party from understanding transmitted raw to maintain a private information link [5]. This requirement data over unsecured channel during signal transmission. The that both parties have access to the secret key is one of the cryptographic methods for enhancing the security of digital main drawbacks of symmetric key encryption, in compari- contents have gained high significance in the current era. son to public-key encryption. Typical examples symmetric Breach of security and misuse of confidential information algorithms are Advanced Encryption Standard (AES), Blow- that has been intercepted by unauthorized parties are key fish, Tripple Data Encryption Standard (3DES) and Serpent problems that information security tries to solve. [6]. This paper sets out to contribute to the general body of Asymmetric or Public key encryption on the other hand is an knowledge in the area of classical cryptography by develop- encryption method where a message encrypted with a reci- ing a new hybrid way of encryption of plaintext. -
Assignment 4 Task 1: Frequency Analysis (100 Points)
Assignment 4 Task 1: Frequency Analysis (100 points) The cryptanalyst can benefit from some inherent characteristics of the plaintext language to launch a statistical attack. For example, we know that the letter E is the most frequently used letter in English text. The cryptanalyst finds the mostly-used character in the ciphertext and assumes that the corresponding plaintext character is E. After finding a few pairs, the analyst can find the key and use it to decrypt the message. To prevent this type of attack, the cipher should hide the characteristics of the language. Table 1 contains frequency of characters in English. Table 1 Frequency of characters in English Cryptogram puzzles are solved for enjoyment and the method used against them is usually some form of frequency analysis. This is the act of using known statistical information and patterns about the plaintext to determine it. In cryptograms, each letter of the alphabet is encrypted to another letter. This table of letter-letter translations is what makes up the key. Because the letters are simply converted and nothing is scrambled, the cipher is left open to this sort of analysis; all we need is that ciphertext. If the attacker knows that the language used is English, for example, there are a great many patterns that can be searched for. Classic frequency analysis involves tallying up each letter in the collected ciphertext and comparing the percentages against the English language averages. If the letter "M" is most common then it is reasonable to guess that "E"-->"M" in the cipher because E is the most common letter in the English language. -
John F. Byrne's Chaocipher Revealed
John F. Byrne’s Chaocipher Revealed John F. Byrne’s Chaocipher Revealed: An Historical and Technical Appraisal MOSHE RUBIN1 Abstract Chaocipher is a method of encryption invented by John F. Byrne in 1918, who tried unsuccessfully to interest the US Signal Corp and Navy in his system. In 1953, Byrne presented Chaocipher-encrypted messages as a challenge in his autobiography Silent Years. Although numerous students of cryptanalysis attempted to solve the challenge messages over the years, none succeeded. For ninety years the Chaocipher algorithm was a closely guarded secret known only to a handful of persons. Following fruitful negotiations with the Byrne family during the period 2009-2010, the Chaocipher papers and materials have been donated to the National Cryptologic Museum in Ft. Meade, MD. This paper presents a comprehensive historical and technical evaluation of John F. Byrne and his Chaocipher system. Keywords ACA, American Cryptogram Association, block cipher encryption modes, Chaocipher, dynamic substitution, Greg Mellen, Herbert O. Yardley, John F. Byrne, National Cryptologic Museum, Parker Hitt, Silent Years, William F. Friedman 1 Introduction John Francis Byrne was born on 11 February 1880 in Dublin, Ireland. He was an intimate friend of James Joyce, the famous Irish writer and poet, studying together in Belvedere College and University College in Dublin. Joyce based the character named Cranly in Joyce’s A Portrait of the Artist as a Young Man on Byrne, used Byrne’s Dublin residence of 7 Eccles Street as the home of Leopold and Molly Bloom, the main characters in Joyce’s Ulysses, and made use of real-life anecdotes of himself and Byrne as the basis of stories in Ulysses. -
De Ornanda Instruendaque Urbe Anne Truetzel
Washington University in St. Louis Washington University Open Scholarship All Theses and Dissertations (ETDs) 1-1-2011 De Ornanda Instruendaque Urbe Anne Truetzel Follow this and additional works at: https://openscholarship.wustl.edu/etd Recommended Citation Truetzel, Anne, "De Ornanda Instruendaque Urbe" (2011). All Theses and Dissertations (ETDs). 527. https://openscholarship.wustl.edu/etd/527 This Thesis is brought to you for free and open access by Washington University Open Scholarship. It has been accepted for inclusion in All Theses and Dissertations (ETDs) by an authorized administrator of Washington University Open Scholarship. For more information, please contact [email protected]. WASHINGTON UNIVERSITY Department of Classics De Ornanda Instruendaque Urbe: Julius Caesar’s Influence on the Topography of the Comitium-Rostra-Curia Complex by Anne E. Truetzel A thesis presented to the Graduate School of Arts and Sciences of Washington University in partial fulfillment of the requirements for the degree of Master of Arts August 2011 Saint Louis, Missouri ~ Acknowledgments~ I would like to take this opportunity to thank the Classics department at Washington University in St. Louis. The two years that I have spent in this program have been both challenging and rewarding. I thank both the faculty and my fellow graduate students for allowing me to be a part of this community. I now graduate feeling well- prepared for the further graduate study ahead of me. There are many people without whom this project in particular could not have been completed. First and foremost, I thank Professor Susan Rotroff for her guidance and support throughout this process; her insightful comments and suggestions, brilliant ideas and unfailing patience have been invaluable.