The Zschweigert Cryptograph – a Remarkable Early Encryption Machine
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A Cipher Based on the Random Sequence of Digits in Irrational Numbers
https://doi.org/10.48009/1_iis_2016_14-25 Issues in Information Systems Volume 17, Issue I, pp. 14-25, 2016 A CIPHER BASED ON THE RANDOM SEQUENCE OF DIGITS IN IRRATIONAL NUMBERS J. L. González-Santander, [email protected], Universidad Católica de Valencia “san Vicente mártir” G. Martín González. [email protected], Universidad Católica de Valencia “san Vicente mártir” ABSTRACT An encryption method combining a transposition cipher with one-time pad cipher is proposed. The transposition cipher prevents the malleability of the messages and the randomness of one-time pad cipher is based on the normality of "almost" all irrational numbers. Further, authentication and perfect forward secrecy are implemented. This method is quite suitable for communication within groups of people who know one each other in advance, such as mobile chat groups. Keywords: One-time Pad Cipher, Transposition Ciphers, Chat Mobile Groups Privacy, Forward Secrecy INTRODUCTION In cryptography, a cipher is a procedure for encoding and decoding a message in such a way that only authorized parties can write and read information about the message. Generally speaking, there are two main different cipher methods, transposition, and substitution ciphers, both methods being known from Antiquity. For instance, Caesar cipher consists in substitute each letter of the plaintext some fixed number of positions further down the alphabet. The name of this cipher came from Julius Caesar because he used this method taking a shift of three to communicate to his generals (Suetonius, c. 69-122 AD). In ancient Sparta, the transposition cipher entailed the use of a simple device, the scytale (skytálē) to encrypt and decrypt messages (Plutarch, c. -
The Enigma Encryption Machine and Its Electronic Variant
The Enigma Encryption Machine and its Electronic Variant Michel Barbeau, VE3EMB What is the Enigma? possible initial settings, making the total number of initial settings in the order of 10 power 16. The The Enigma is a machine devised for encrypting initial setting, taken from a code book, indicates plain text into cipher text. The machine was which pairs of letters (if any) are switched with each invented in 1918 by the German engineer Arthur other. The initial setting is called the secret key. Scherbius who lived from 1878 to 1929. The German Navy adopted the Enigma in 1925 to secure World War II was fought from 1939 to 1945 their communications. The machine was also used between the Allies (Great Britain, Russia, the by the Nazi Germany during World War II to cipher United States, France, Poland, Canada and others) radio messages. The cipher text was transmitted in and the Germans (with the Axis). To minimize the Morse code by wireless telegraph to the destination chance of the Allies cracking their code, the where a second Enigma machine was used to Germans changed the secret key each day. decrypt the cipher text back into the original plain text. Both the encrypting and decrypting Enigma The codes used for the naval Enigmas, had machines had identical settings in order for the evocative names given by the germans. Dolphin decryption to succeed. was the main naval cipher. Oyster was the officer’s variant of Dolphin. Porpoise was used for The Enigma consists of a keyboard, a scrambling Mediterranean surface vessels and shipping in the unit, a lamp board and a plug board. -
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 -
Pioneers in U.S. Cryptology Ii
PIONEERS IN U.S. CRYPTOLOGY II This brochure was produced by the Center for Cryptologic History Herbert 0. Yardley 2 Herbert 0. Yardley Herbert 0 . Yardley was born in 1889 in Worthington, Indiana. After working as a railroad telegrapher and spending a year taking an English course at the University of Chicago, he became a code clerk for the Department of State. In June 1917, Yardley received a commission in the Signal Officers Reserve Corps; in July Colonel Ralph Van Deman appointed him chief of the new cryptanalytic unit, MI-8, in the Military Intelligence division. MI-8, or the Cipher Bureau, consisted of Yardley and two clerks. At MI-8's peak in November 1918, Yardley had 18 officers, 24 civilians, and 109 typists. The section had expanded to include secret inks, code and cipher compilation, communications, and shorthand. This was the first formally organized cryptanalytic unit in the history of the U.S. government. When World War I ended, the Army was considering disbanding MI-8. Yardley presented a persuasive argument for retaining it for peacetime use. His plan called for the permanent retention of a code and cipher organization funded jointly by the State and War Departments. He demonstrated that in the past eighteen months MI-8 had read almost 11,000 messages in 579 cryptographic systems. This was in addition to everything that had been examined in connection with postal censorship. On 17 May Acting Secretary of State Frank L. Polk approved the plan, and two days later the Army Chief of Staff, General Peyton C. -
Historical Ciphers Systems Top 10 Open Problems May 5, 2016 George Lasry [email protected] Open Problems - Criteria
Historical Ciphers Systems Top 10 Open Problems May 5, 2016 George Lasry [email protected] Open Problems - Criteria • Generic method vs. deciphering a document • System details are known – For many there are simulators • Published methods vs. classified • General vs. special case solutions – Ciphertext only vs. known plaintext – Single message vs. in-depth messages – Short vs. long messages – Long vs. short keys • Brute force not feasible – But computer most likely required George Lasry May 2016 2 Top 10 Open Problems 1. SIGABA 2. KL-7 3. Siemens T52D “Sturgeon” 4. Hagelin CX-52 5. Fialka 6. Lorenz SZ42 “Tunny” – Ψ1 limitation 7. Hagelin M-209 – short messages 8. Double Transposition – long random keys 9. Enigma – short message 10. Chaocipher – single message George Lasry May 2016 3 Problem 1: SIGABA (US) • Possible keys (WWII): 2 96 = 10 29 • Best published: known-plaintext 2 60 = 10 18 steps George Lasry May 2016 4 Problem 2: KL-7 (US) • Details of the machine known (+ simulator) • Best published cryptanalytic method: None! George Lasry May 2016 5 Problem 3: Siemens & Halske T52D • Successor of T52a/b/c: Irregular wheel stepping • Possible key settings: 2 73 = 10 24 • Best published method: > 5 messages in depth George Lasry May 2016 6 Problem 4: Hagelin CX-52 • Successor of C38/M209: Irregular wheel stepping • Possible key settings: 2 439 = 10 132 • Best published method: Known-plaintext George Lasry May 2016 7 Problem 5: Fialka M-125 (Russia) • Possible key settings: 2 250 = 10 75 • Best published method: None! George -
An Archeology of Cryptography: Rewriting Plaintext, Encryption, and Ciphertext
An Archeology of Cryptography: Rewriting Plaintext, Encryption, and Ciphertext By Isaac Quinn DuPont A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Faculty of Information University of Toronto © Copyright by Isaac Quinn DuPont 2017 ii An Archeology of Cryptography: Rewriting Plaintext, Encryption, and Ciphertext Isaac Quinn DuPont Doctor of Philosophy Faculty of Information University of Toronto 2017 Abstract Tis dissertation is an archeological study of cryptography. It questions the validity of thinking about cryptography in familiar, instrumentalist terms, and instead reveals the ways that cryptography can been understood as writing, media, and computation. In this dissertation, I ofer a critique of the prevailing views of cryptography by tracing a number of long overlooked themes in its history, including the development of artifcial languages, machine translation, media, code, notation, silence, and order. Using an archeological method, I detail historical conditions of possibility and the technical a priori of cryptography. Te conditions of possibility are explored in three parts, where I rhetorically rewrite the conventional terms of art, namely, plaintext, encryption, and ciphertext. I argue that plaintext has historically been understood as kind of inscription or form of writing, and has been associated with the development of artifcial languages, and used to analyze and investigate the natural world. I argue that the technical a priori of plaintext, encryption, and ciphertext is constitutive of the syntactic iii and semantic properties detailed in Nelson Goodman’s theory of notation, as described in his Languages of Art. I argue that encryption (and its reverse, decryption) are deterministic modes of transcription, which have historically been thought of as the medium between plaintext and ciphertext. -
Taschenchiffriergerat CD-57 Seite 1
s Taschenchiffriergerat CD-57 Seite 1 Ubung zu Angewandter Systemtheorie Kryptog raph ie SS 1997 - Ubungsleiter^ Dr. Josef Scharinger Taschenchiffriergerat CD-57 Michael Topf, Matr.Nr. 9155665, Kennz. 880 <?- Cm Johannes Kepler Universitat Linz Institut fur Systemwissenschaften Abteilung fur Systemtheorie und Informationstechnik Michael Topf Ubung zu Angewandter Systemtheorie: Kryptographic Seite 2 Taschenchiffriergerat CD-57 I n ha I ts verzei c h n i s I n h a l t s v e r z e i c h n i s 2 Einleitung 3 B o r i s H a g e l i n 3 Die Hagelin M-209 Rotormaschine 3 Das Taschenchiffriergerat CD-57 4 Die Crypto AG 5 Funktionsweise 6 Kryptographisches Prinzip 6 Mechanische Realisierung 7 Black-Box-Betrachtung 7 S c h i e b e r e g i s t e r 8 Ausgangsgewichtung und Summierung. 8 Daten 9 Anfangszustand der Schieberegister (Stiftposition) 9 Gewichtung der Schieberegister-Ausgange (Position der Anschlage) 9 Softwaremodell \\ Quelltext «CD-57.C » \\ Beispiel 12 Schliisseleinstellungen « Schluessel.txt » 12 Primartext « Klartext.txt » 13 Programmaufruf 13 Sekundartext « Geheimtext.txt » 13 Abbildungsverzeichnis 14 Tabellenverzeichnis 14 Quellenverzeichnis , 14 Ubung zu Angewandter Systemtheorie: Kryptographie Michael Topf Taschenchiffriergerat CD-57 Seite 3 Ei nleitu ng Der geistige Vater des betrachtelen Chiffriergerats sowie einer Reihe verwandter Gerate ist der Schwede Boris Hagelin. Daher sollen einleitend er, die Familie der Rotor-Kryptographierer sowie die von ihm gegriindete Schweizer Firma Crypto AG, vorgestellt werden. B o r i s H a g e l i n Boris Hagelin war ein Visionar, der bereits zu seiner Zeit die Probleme der Informationstechnologie erkannte. -
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. -
Grade 6 Math Circles Cryptography Solutions Atbash Cipher Caesar Cipher
Faculty of Mathematics Centre for Education in Waterloo, Ontario N2L 3G1 Mathematics and Computing Grade 6 Math Circles November 5/6 2019 Cryptography Solutions Hello World Khoor Zruog Hello Zruog Khoor Khoor Zruog World 1. Person A encrypts plaintext 2. Person B receives ciphertext 3. Person B decrypts ciphertext back into ciphertext into plaintext Atbash Cipher Examples 1. Encrypt \Math Circles" using the Atbash cipher. Nzgs Xrixovh 2. Decrypt \ORLM PRMT" using the Atbash cipher. LION KING Caesar Cipher Examples: Encrypt or decrypt the following messages using the shift number given in parentheses: a) Welcome to Math Circles! (5) Bjqhtrj yt Rfym Hnwhqjx! plaintext A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ciphertext F G H I J K L M N O P Q R S T U V W X Y Z A B C D E 1 b) Ljw hxd anjm cqrb? (9) Can you read this? plaintext A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ciphertext J K L M N O P Q R S T U V W X Y Z A B C D E F G H I c) What if I did a Caesar Shift of 26 units on \Welcome to Math Circles!"? A Caesar shift of 26 would be shifting by the length of the alphabet. For example I would be shifting A 26 letters to the right. -
Breaking Transposition Cipher with Genetic Algorithm
Breaking Transposition Cipher with Genetic Algorithm C.Obi Reddy, National University of Singapore(NUS), ECE Department, [email protected] Abstract: In recent years a number of example total number of letters is 20 optimisation algorithms have emerged which is regular case with the key order of which have proven to be effective in 5. If the plain text is irregular then solving a variety of NP-complete padding of X is done at the tail of the text problems. In this paper an example the to make it regular. kind in cryptanalysis, breaking of Encryption of plain text is done as follows transposition cipher using a heuristic genetic algorithm is presented. Regular: Plain 1 2 3 4 5 Introduction: Text In the Brute Force attack the attacker Key 1 4 2 5 3 tries every possible (k! Keys) key on a T H I S I piece of cipher text until an intelligible S A S I M translation into plaintext is obtained. P L E M E Many types of classical ciphers exist, S S A G E although most fall into one of two broad categories: substitution ciphers and Cipher Text: TSPS ISEA IMEE HALS SIMG transposition ciphers. In the former one, every plaintext character is substituted by Irregular: a cipher character, using a substitution Plain 1 2 3 4 5 alphabet, and in the latter one, plaintext Text characters are permuted using a Key 1 4 2 5 3 predetermined permutation. T H I S I S A S I M Transposition cipher works by breaking P L E M E the plain text in to fixed number of blocks S S A G E and then shuffling the characters in each block according to the agreed key K. -
William F. Friedman, Notes and Lectures
f?~~A63403 SECOND PERIOD _ COMMUNICATIONS SECURITY Gentl.emen, this period will be devoted to_the subject of communications security, how it can be establ.ished and maintained. Three or four years ago I gave a talk before the student officers of another Service School. on this subject. About that time there was being hammered into our ears over the radio in Washington a sl.ogan concerned with automobil.e traffic safety rul.es. The sl.oga.n was: "Don't l.earn your traffic l.aws by accident." I thought the sl.ogan useful. as a titl.e for my tal.k but I modified it a l.ittl.e-- Don't l.earn your COMSEC l.aws by accident. I began my tal.k on that occasion, as on this one, by reading the Webster Dictionary definition of the word "accident". I know, of course, that this group here today is not directl.y concerned with COMSEC duties but as potential. future cQJD17!8nders of fighting units the definition of' the word "accident11 shoul.d be of' interest in connection with what wil.l. be said in a moment or two, so I wil.l. read Webster's definition if' you wil.l. bear with me. "Accident: Literally a befal.l.ing,; an event which takes pl.ace without one •s foresight or 7x~ctation,; an undesigned, sudden and unexpected ' event, hence, often an undesigned or unforeseen occurrence of an " affl.ictive or unfortunate character; a mishap resul.ting in injury to a person or damage to a thing; a casual.ty, as to die by accident." . -
Lecture 2: Classical Cryptography
Lecture 2: Classical Cryptography Data and Information Management: ELEN 3015 School of Electrical and Information Engineering, University of the Witwatersrand Introduction Monoalphabetic Cipher - Frequency analysis Classical Ciphers Other Substitution Ciphers Transposition ciphers Stream vs Block Enciphering 1. Homework hqfubswlrq lv d phdqv ri dwwdlqlqj vhfxuh frpsxwdwlrq ryhu lqvhfxuh fkdqqhov eb xvlqj hqfubswlrq zh glvjxlvh wkh phvvdjh vr wkdw hyhq li wkh wudqvplvvlrq lv glyhuwhg wkh phvvdjh zloo qrw eh uhyhdohg 1. Monoalphabetic Cipher - Frequency analysis Do a frequency analysis Letter distribution of English language is fixed (for a large body of text) Tables of letter distribution For instance, most commonly used letter is \e" 1. Monoalphabetic Cipher - Frequency analysis 1. Monoalphabetic Cipher - Answer ENCRYPTION IS A MEANS OF ATTAINING SECURE COMMUNICATION OVER INSECURE CHANNELS BY USING ENCRYPTION WE DISGUISE THE MESSAGE SO THAT EVEN IF THE TRANSMISSION IS DIVERTED THE MESSAGE WILL NOT BE REVEALED 2. Classical Ciphers How do we increase security of the monoalphabetic cipher? 3. Polyalphabetic ciphers Use more than one alphabetic substitution to flatten the frequency distribution Combine substitutions that are high with those that are low Eg use: • P1(a) = (a*3)mod26 • P2(a) = ((5*a)+13)mod26 3. Polyalphabetic ciphers Cipher I: ABCDEFG ::: STUVWXYZ a d g j m p s ::: c f i l o r u x Cipher II: ABCDEFG ::: STUVWXYZ n s x c h m r ::: z e j o t y d i 3. Polyalphabetic ciphers - Frequency distribution 3. Vigenere tables a b c d e f ::: t u v w x y z π A a b c d e f ::: t u v w x y z 0 B b c d e f g ::: u v w x y z a 1 C c d e f g h ::: v w x y z a b 2 .