A Systematic Study on Classical Cryptographic Cypher in Order to Design a Smallest Cipher
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Classical Encryption Techniques
CPE 542: CRYPTOGRAPHY & NETWORK SECURITY Chapter 2: Classical Encryption Techniques Dr. Lo’ai Tawalbeh Computer Engineering Department Jordan University of Science and Technology Jordan Dr. Lo’ai Tawalbeh Fall 2005 Introduction Basic Terminology • plaintext - the original message • ciphertext - the coded message • key - information used in encryption/decryption, and known only to sender/receiver • encipher (encrypt) - converting plaintext to ciphertext using key • decipher (decrypt) - recovering ciphertext from plaintext using key • cryptography - study of encryption principles/methods/designs • cryptanalysis (code breaking) - the study of principles/ methods of deciphering ciphertext Dr. Lo’ai Tawalbeh Fall 2005 1 Cryptographic Systems Cryptographic Systems are categorized according to: 1. The operation used in transferring plaintext to ciphertext: • Substitution: each element in the plaintext is mapped into another element • Transposition: the elements in the plaintext are re-arranged. 2. The number of keys used: • Symmetric (private- key) : both the sender and receiver use the same key • Asymmetric (public-key) : sender and receiver use different key 3. The way the plaintext is processed : • Block cipher : inputs are processed one block at a time, producing a corresponding output block. • Stream cipher: inputs are processed continuously, producing one element at a time (bit, Dr. Lo’ai Tawalbeh Fall 2005 Cryptographic Systems Symmetric Encryption Model Dr. Lo’ai Tawalbeh Fall 2005 2 Cryptographic Systems Requirements • two requirements for secure use of symmetric encryption: 1. a strong encryption algorithm 2. a secret key known only to sender / receiver •Y = Ek(X), where X: the plaintext, Y: the ciphertext •X = Dk(Y) • assume encryption algorithm is known •implies a secure channel to distribute key Dr. -
COS433/Math 473: Cryptography Mark Zhandry Princeton University Spring 2017 Cryptography Is Everywhere a Long & Rich History
COS433/Math 473: Cryptography Mark Zhandry Princeton University Spring 2017 Cryptography Is Everywhere A Long & Rich History Examples: • ~50 B.C. – Caesar Cipher • 1587 – Babington Plot • WWI – Zimmermann Telegram • WWII – Enigma • 1976/77 – Public Key Cryptography • 1990’s – Widespread adoption on the Internet Increasingly Important COS 433 Practice Theory Inherent to the study of crypto • Working knowledge of fundamentals is crucial • Cannot discern security by experimentation • Proofs, reductions, probability are necessary COS 433 What you should expect to learn: • Foundations and principles of modern cryptography • Core building blocks • Applications Bonus: • Debunking some Hollywood crypto • Better understanding of crypto news COS 433 What you will not learn: • Hacking • Crypto implementations • How to design secure systems • Viruses, worms, buffer overflows, etc Administrivia Course Information Instructor: Mark Zhandry (mzhandry@p) TA: Fermi Ma (fermima1@g) Lectures: MW 1:30-2:50pm Webpage: cs.princeton.edu/~mzhandry/2017-Spring-COS433/ Office Hours: please fill out Doodle poll Piazza piaZZa.com/princeton/spring2017/cos433mat473_s2017 Main channel of communication • Course announcements • Discuss homework problems with other students • Find study groups • Ask content questions to instructors, other students Prerequisites • Ability to read and write mathematical proofs • Familiarity with algorithms, analyZing running time, proving correctness, O notation • Basic probability (random variables, expectation) Helpful: • Familiarity with NP-Completeness, reductions • Basic number theory (modular arithmetic, etc) Reading No required text Computer Science/Mathematics Chapman & Hall/CRC If you want a text to follow along with: Second CRYPTOGRAPHY AND NETWORK SECURITY Cryptography is ubiquitous and plays a key role in ensuring data secrecy and Edition integrity as well as in securing computer systems more broadly. -
A Secure Authentication System- Using Enhanced One Time Pad Technique
IJCSNS International Journal of Computer Science and Network Security, VOL.11 No.2, February 2011 11 A Secure Authentication System- Using Enhanced One Time Pad Technique Raman Kumar1, Roma Jindal 2, Abhinav Gupta3, Sagar Bhalla4 and Harshit Arora 5 1,2,3,4,5 Department of Computer Science and Engineering, 1,2,3,4,5 D A V Institute of Engineering and Technology, Jalandhar, Punjab, India. Summary the various weaknesses associated with a password have With the upcoming technologies available for hacking, there is a come to surface. It is always possible for people other than need to provide users with a secure environment that protect their the authenticated user to posses its knowledge at the same resources against unauthorized access by enforcing control time. Password thefts can and do happen on a regular basis, mechanisms. To counteract the increasing threat, enhanced one so there is a need to protect them. Rather than using some time pad technique has been introduced. It generally random set of alphabets and special characters as the encapsulates the enhanced one time pad based protocol and provides client a completely unique and secured authentication passwords we need something new and something tool to work on. This paper however proposes a hypothesis unconventional to ensure safety. At the same time we need regarding the use of enhanced one time pad based protocol and is to make sure that it is easy to be remembered by you as a comprehensive study on the subject of using enhanced one time well as difficult enough to be hacked by someone else. -
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. -
Battle Management Language: History, Employment and NATO Technical Activities
Battle Management Language: History, Employment and NATO Technical Activities Mr. Kevin Galvin Quintec Mountbatten House, Basing View, Basingstoke Hampshire, RG21 4HJ UNITED KINGDOM [email protected] ABSTRACT This paper is one of a coordinated set prepared for a NATO Modelling and Simulation Group Lecture Series in Command and Control – Simulation Interoperability (C2SIM). This paper provides an introduction to the concept and historical use and employment of Battle Management Language as they have developed, and the technical activities that were started to achieve interoperability between digitised command and control and simulation systems. 1.0 INTRODUCTION This paper provides a background to the historical employment and implementation of Battle Management Languages (BML) and the challenges that face the military forces today as they deploy digitised C2 systems and have increasingly used simulation tools to both stimulate the training of commanders and their staffs at all echelons of command. The specific areas covered within this section include the following: • The current problem space. • Historical background to the development and employment of Battle Management Languages (BML) as technology evolved to communicate within military organisations. • The challenges that NATO and nations face in C2SIM interoperation. • Strategy and Policy Statements on interoperability between C2 and simulation systems. • NATO technical activities that have been instigated to examine C2Sim interoperation. 2.0 CURRENT PROBLEM SPACE “Linking sensors, decision makers and weapon systems so that information can be translated into synchronised and overwhelming military effect at optimum tempo” (Lt Gen Sir Robert Fulton, Deputy Chief of Defence Staff, 29th May 2002) Although General Fulton made that statement in 2002 at a time when the concept of network enabled operations was being formulated by the UK and within other nations, the requirement remains extant. -
Amy Bell Abilene, TX December 2005
Compositional Cryptology Thesis Presented to the Honors Committee of McMurry University In partial fulfillment of the requirements for Undergraduate Honors in Math By Amy Bell Abilene, TX December 2005 i ii Acknowledgements I could not have completed this thesis without all the support of my professors, family, and friends. Dr. McCoun especially deserves many thanks for helping me to develop the idea of compositional cryptology and for all the countless hours spent discussing new ideas and ways to expand my thesis. Because of his persistence and dedication, I was able to learn and go deeper into the subject matter than I ever expected. My committee members, Dr. Rittenhouse and Dr. Thornburg were also extremely helpful in giving me great advice for presenting my thesis. I also want to thank my family for always supporting me through everything. Without their love and encouragement I would never have been able to complete my thesis. Thanks also should go to my wonderful roommates who helped to keep me motivated during the final stressful months of my thesis. I especially want to thank my fiancé, Gian Falco, who has always believed in me and given me so much love and support throughout my college career. There are many more professors, coaches, and friends that I want to thank not only for encouraging me with my thesis, but also for helping me through all my pursuits at school. Thank you to all of my McMurry family! iii Preface The goal of this research was to gain a deeper understanding of some existing cryptosystems, to implement these cryptosystems in a computer programming language of my choice, and to discover whether the composition of cryptosystems leads to greater security. -
Affine Cipher Project 1 Introduction
Affine Cipher Project 141KECBZ0H5CRK1HUZK1CGPCR.5PUGUZU1WCU.CM1CUBHUCAK.6.Z5WCP1RK1UCH5 WC0EPU1KECU.C141KEC.UB1KXC,,RBHKV1PCWGRQ15P7CHCUHV1C.6CU9.CRGUG1P Directions: • Answer all numbered questions completely. • Show non-trivial work, and put your final answer in the box provided. • Questions without boxes should be answered in complete sentences in the space provided. 1 Introduction Cryptography is the study of secret codes, or the secure transmission of information that nobody except the desired recipient can read. By the end of this project, you will be able to decipher the quote printed above. The mathematical study of ciphers will lead us through a world in which the number line is a closed curve, and fractions do not exist. This project is designed to help you to: • read and understand definitions and notation • observe patterns and generalize • think logically, analytically, and abstractly • express problems and solutions precisely • follow examples • combine ideas to solve problems and create applications 1 2 Caesar Cipher A cipher is a function or algorithm for translating plaintext into encrypted ciphertext. Throughout history, governments and merchants have used ciphers to safely transmit sensitive information. Julius Caesar is said to have use a simple system of substituting each letter with the letter 3 spots over, wrapping around the alphabet if necessary. Here is the mapping: 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 # # # # # # # # # # # # # # # # # # # # # # # # # # D E F G H I J K L M N O P Q R S T U V W X Y Z A B C Space and punctuation are discarded. -
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. -
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IJCSI International Journal of Computer Science Issues, Vol. 10, Issue 4, No 2, July 2013 ISSN (Print): 1694-0814 | ISSN (Online): 1694-0784 www.IJCSI.org 89 An Eccentric Scheme for Oblivious Communication Khan Farhan Rafat and Muhammad Sher Department of Computer Science, International Islamic University Islamabad, 44000, Pakistan alphabets and then threading the yarn through these holes Abstract in an order which when detached spelt out letters of hidden Trust is the foremost requirement in any form of communication. message in its correct sequence [3]: Building trust through physical contact, gesture etc. is easy but hard to establish in electronic data communication as one can’t “padielaporsymesarponomeuaspeludynmalpreaxo” be sure of the presence of the intended recipient at the other end. “Ave Maria” is yet another smart method for encoding This necessitated the need to devise and suggest covert schemes secret message where list of distinct words for each unique for oblivious communication that only the intended recipient may alphabet are grouped in a series of Tables. For every unveil. Steganography is one such technique where information alphabet constituting the message, word corresponding to to be sent is seamlessly superimposed on the carrier such that it that letter from the set of Tables gets substituted and easily crosses the information confronting barriers without appeared as innocent rhyme whenever the Tables are used detection. This paper endeavors at evolving a data hiding scheme in sequence. envisaged by Shannon and in adherence to Kerchoff’s principle that hides secret information inside statistically random English Cardano introduced the “Grille System” [4] where every alphabets appearing as cryptogram. -
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 -
The Solving of a Fleissner Grille During an Exercise by the Royal Netherlands Army in 1913
The Solving of a Fleissner Grille during an Exercise by the Royal Netherlands Army in 1913 Karl de Leeuw University of Amsterdam / Informatics Institute Science Park 904, 1098 XH Amsterdam [email protected] Abstract Initially the grille was intended for hiding that a secret message was being sent at all, rather than In 1885 the General Staff of the Royal as a means of encryption. This all changed dur- Netherlands Army had adopted a variant ing the course of the 18th century, when the grille of the turning grille devised by Edouard was increasingly used for jumbling the characters Fleissner von Wostrowitz as a means for in a message by rotating them, according to the encrypting messages, exchanged by tele- holes in the mask. The first description of such graph between the General Headquarters use we find by the German mathematician Carl and commanders in the field. Some staff Friedrich von Hindenburg (1796) who was aware members harbored serious doubts about that such use could only be made at the expense the security of this device, however, and of a loss in entropy and, therefore, cryptographic during a military exercise in 1913 it was strength. The perforation pattern in one quadrant solved with surprising ease by an army of the mask would automatically limit the possi- captain. The matter was investigated by bilities for perforation in all others, because two a committee of staff officers, concluding punch holes could not be allowed to cover the that the army lacked the expertise to judge same position after a rotation.