DOCSLIB.ORG

Research on Various Cryptography Techniques

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Research on Various Cryptography Techniques International Journal of Recent Technology and Engineering (IJRTE) ISSN: 2277-3878, Volume-8, Issue-2S3, July 2019 Research on Various Cryptography Techniques Yahia Alemami, Mohamad Afendee Mohamed, Saleh Atiewi ABSTRACT--- Security plays a critical position in preserving information privacy and secrecy. Many encryption strategies are available to protect data during transmission or storage. These encryption methods vary in terms of strength, speed, and resource consumption (CPU usage, memory, and power). This study aims to present the most popular and interesting algorithms currently in use. Fig. 2: Asymmetric cryptosystem Index Terms — Cryptography, data security, public key, resource consumption, secret key. A. Common Terms Used in Cryptography I. INTRODUCTION Plaintext: The original and understandable text. As an instance, 'Y' needs to transmit a “Computer” message Security is an important in protecting data against to 'Z'. Here, “Computer” is the plaintext or the original intruders. One of the most important methods for ensuring message. data secrecy is cryptography. Cryptography is secret writing Ciphertext: The text that cannot be understood by way for data security protection. Well-hidden data cannot of anybody or a gibberish text, example “A@$&J9.” easily be read, modified or fabricated [1]. Cryptography Encryption: A process of changing clear text into protects crucial data via changing it into unclear data that unclear text. The manner of encipherment needs an can only be accessed via authorized receivers, who then encipherment algorithm and a key. Encipherment converts the uncertain data into the original textual content. occurs on the sender side. The process of changing original text into unclear text Decryption: A reverse method of encode. It is a (ciphertext) with a certain key referred to as encryption, and manner of converting ciphertext into plaintext. the opposite of encryption process is referred to as Key: A key is character, number, or a special decryption process. character. It is used at the time of encipherment on the Privacy and security management present challenges to e- original text and at the time of decode on the exam. An e-exam database requires security and reliability. ciphertext. Thus, an e-exam user’s identity must be established. Computerized exams are prone to significant problems such B. Purpose of Cryptography as leaks, attackers and so on. One solution is to encrypt the Authentication: The potential of a system to test the questions inside the database. Encryption is the conversion identity of the sender. of plaintext to text that is not clear. Confidentiality: Information transmitted ought to be The two fundamental techniques for encrypting data are accessed handiest by using legal parties and not “symmetric cryptography,” which entails the usage of the through anyone else. same key to encrypt/ decode information; and “asymmetric Integrity: Only the authorized parties are permitted to cryptography,” which makes use of public and private keys alter on transmitted information. to encrypt/ decode information. Non-repudiation: Is the guarantee that someone Examples of symmetric algorithms are Data Encryption cannot deny the validity of something. Standard (DES), Triple-DES (3DES), Blowfish, and Advanced Encryption Standard (AES). The most well- Access Control: Just the authorized persons are known asymmetric algorithms are RSA and ELGAMAL capable to get right of entry to the given information. Schema. C. Evaluation Parameters Each encryption algorithm presents strengths and weaknesses in terms of their parameters. Some parameters that determine encryption performance are described as follows. 1) Encryption time: Measured in milliseconds, depend on Fig. 1. Symmetric cryptosystem the data block length and key length. It directly influences the performance of the encryption algorithm. The performance of an algorithm is regarded as advanced when the encryption time is rapid. Revised Manuscript Received on July 10, 2019. Yahia Alemami, Faculty of Informatics and Computing, Universiti Sultan Zainal Abidin, Terengganu, Malaysia. Mohamad Afendee Mohamed, Faculty of Informatics and Computing, Universiti Sultan Zainal Abidin, Terengganu, Malaysia. Saleh Atiewi, Computer Science, Al Hussein Bin Talal University College of IT, Ma’an, Jordan. Published By: Retrieval Number: B10690782S319/19©BEIESP Blue Eyes Intelligence Engineering DOI : 10.35940/ijrte.B1069.0782S319 395 & Sciences Publication RESEARCH ON VARIOUS CRYPTOGRAPHY TECHNIQUES 2) Decryption time: The time period to regain the follows: The 8-bit input to fK is divided into left and original text from ciphertext; it is also measured in right inputs, each of which contains 4 bits for use in milliseconds. The performance of an algorithm is the following equation: fK(L, R) = (L (XOR) F(R, regarded as superior when the decryption time is SK), R) where SK is a subkey and XOR is the bit-by- rapid. bit exclusive-OR function. The initial process is an 3) Memory used: A low memory usage is desirable expansion/permutation process. because it affects system cost. 4) Throughput: Is computed through way of dividing the whole encoded block size on the entire encode time. The fundamental 4 bits are fed inside the S-box S0 to The power consumption of the algorithm will supply a 2-bit outcome, and the residual 4 bits are fed inside decrease, if the throughput cost increases [2]. S1 to provide another 2-bit outcome. These boxes are described as follows: II. ENCRYPTION ALGORITHMS This part clarifies numerous encryption algorithms to identify the best encryption schemes on the basis of various parameters. A. Simplified Data Encryption Standard (S-DES) The steps of the S-DES algorithm described as follows: The S-boxes work as follows: The result of preceding 1) S-DES Key Generation: S-DES relies upon on the steps indicates that the 1st and 4th enter bits are taken into using of a shared key that consist of 10- bit and share consideration a two-bit number that specifies a row of the S- it among both sender and receiver. Pair of 8-bit sub box, and the 2nd and 3rd input bits determine a column of the keys are generated (K1, K2) from this key for use in S-box. S0 is used by the left nibble, and S1 is used by the specific stages of encipherment and decipherment right nibble. The following 4 bits generated through S0 and algorithms as presented in Fig. 3 [3]. S1 undergo further permutation as follows: Both Fig. 4 and 5 illustrate the S-DES. Fig. 3: Key generation for S-DES [3] Both keys are coming through using the functions P10, Shift and P8 where P10 and P8 are as follows: 2) Initial and Final Permutations: The input to the Fig. 4: S-DES scheme [4] algorithm is an eight-bit block of original text, which is initially permuted using the IP function with IP given as follows: At the end of the algorithm, the inverse permutation, IP−1 is applied; here, IP−1 is given as follows: 3) Function fK: This function can be explained as Published By: Retrieval Number: B10690782S319/19©BEIESP Blue Eyes Intelligence Engineering DOI : 10.35940/ijrte.B1069.0782S319 396 & Sciences Publication International Journal of Recent Technology and Engineering (IJRTE) ISSN: 2277-3878, Volume-8, Issue-2S3, July 2019 Fig. 6: Blowfish encryption algorithm [2] Fig. 5: S-DES encryption detail [4] E. Advanced Encryption Standard (AES) B. DES AES was deployment by the National Institute of Standards and Technology in 2001; it is also called DES is the earliest symmetric encipherment algorithm “Rijndael” [5]. introduced in 1972 by International Business Machines AES is a block cipher with a block size of 128 bits. The Corporation and in 1977 it has been Agreed as Federal key length can be 128, 192 or 256 bits. Encipherment Information Processing Standard through the National includes ten rounds of processing for 128-bit keys, 12 Bureau of Standard [2]. It comprises the same steps as S- rounds for 192-bit keys and 14 rounds for 256-bit keys. The DES and processes a 64-bit input with a preliminary algorithm is called AES-128, AES-192 or AES-256 relying permutation. In DES, the number of rounds is 16 while in S- on the key size [5]. The steps for every round include of 4 DES is two rounds also the S-DES uses 8 bits for input. layers, particularly, replacement byte, shift rows, blend C. Triple DES (3DES) column and add round key as appear in Fig. 7 [2]. 3DES was suggested by IBM (International Business Machines Corporation) in 1998. A substitute for DES, 3DES shows improved key size and applies the DES algorithm 3 rounds in each data block. The key length for the 3DES is 112 and 168 bits, the number of rounds is 48 and the block length is 64 bits [2]. This algorithm aims to increase protection and security through its longer key size relative to DES. However, it is more time consuming than DES is when applied to the encryption process. D. Blowfish Blowfish is a type of symmetric block cipher generated by B. Schneier in 1993. Blowfish is fast algorithm, license free, and unpatented. It uses a key length in the range of 32– 448 and a sixty-four-bit block. The Blowfish algorithm makes use 16 round for the encipherment procedure Fig. 6. Blowfish ordinarily makes use of 4 S-boxes rather than of one S-box. It requires additional processing time because it relies on key length, however it provides strong safety [2]. Fig. 7: AES algorithm [2] Published By: Retrieval Number: B10690782S319/19©BEIESP Blue Eyes Intelligence Engineering DOI : 10.35940/ijrte.B1069.0782S319 397 & Sciences Publication RESEARCH ON VARIOUS CRYPTOGRAPHY TECHNIQUES III. LITERATURE REVIEW & RESULTS The Diffie–Hellman protocol has been applied to many A secure socket layer (SSL) channel guarantees that all security protocols including SSL, secure shell and IP information passed between the web server and the browser security [13].
Load more

Recommended publications
  • A Covert Encryption Method for Applications in Electronic Data Interchange
    Technological University Dublin ARROW@TU Dublin Articles School of Electrical and Electronic Engineering 2009-01-01 A Covert Encryption Method for Applications in Electronic Data Interchange Jonathan Blackledge Technological University Dublin, [email protected] Dmitry Dubovitskiy Oxford Recognition Limited, [email protected] Follow this and additional works at: https://arrow.tudublin.ie/engscheleart2 Part of the Digital Communications and Networking Commons, Numerical Analysis and Computation Commons, and the Software Engineering Commons Recommended Citation Blackledge, J., Dubovitskiy, D.: A Covert Encryption Method for Applications in Electronic Data Interchange. ISAST Journal on Electronics and Signal Processing, vol: 4, issue: 1, pages: 107 -128, 2009. doi:10.21427/D7RS67 This Article is brought to you for free and open access by the School of Electrical and Electronic Engineering at ARROW@TU Dublin. It has been accepted for inclusion in Articles by an authorized administrator of ARROW@TU Dublin. For more information, please contact [email protected], [email protected]. This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License A Covert Encryption Method for Applications in Electronic Data Interchange Jonathan M Blackledge, Fellow, IET, Fellow, BCS and Dmitry A Dubovitskiy, Member IET Abstract— A principal weakness of all encryption systems is to make sure that the ciphertext is relatively strong (but not that the output data can be ‘seen’ to be encrypted. In other too strong!) and that the information extracted is of good words, encrypted data provides a ‘flag’ on the potential value quality in terms of providing the attacker with ‘intelligence’ of the information that has been encrypted.
    [Show full text]
  • Improved Cryptosystem Using SDES Algorithm with Substitution Ciphers G.Suman * , Ch
    Volume 3, Issue 7, July 2013 ISSN: 2277 128X International Journal of Advanced Research in Computer Science and Software Engineering Research Paper Available online at: www.ijarcsse.com Improved Cryptosystem Using SDES Algorithm with Substitution Ciphers G.Suman * , Ch. Krishna M. Tech (SE) & SNIST. India Abstract— Security is playing a very important and crucial role in the field of network communication system and Internet. Simplified Data encryption standard (SDES) is a private key cryptography system that provides the security in communication system but now a days the advancement in the computational power the SDES seems to be weak against the brute force attacks. To improve the security of SDES algorithm the substitution techniques are added before the SDES algorithm to perform its process. By using an Improved Cryptosystem the security has been improved which is very crucial in the communication and field of Internet. If the substitution techniques are used before the original SDES algorithm then the intruder required first to break the original SDES algorithm and then substitution techniques. So the security is more as compared to a SDES algorithm. Keywords— Cipher text, Decryption, SDES, Encryption, Plain text, OPBFT,OPBTS ,Substitution. I. Introduction The process of encoding the plaintext into cipher text is called Encryption and the process of decoding ciphers text to plaintext is called Decryption. This can be done by two techniques symmetric-key cryptography and asymmetric key cryptography. Symmetric key cryptography involves the usage of the same key for encryption and decryption. But the Asymmetric key cryptography involves the usage of one key for encryption and another different key for decryption.
    [Show full text]
  • Cryptography Using Steganography: New Algorithms and Applications
    Technological University Dublin ARROW@TU Dublin Articles School of Electrical and Electronic Engineering 2011 Cryptography Using Steganography: New Algorithms and Applications Jonathan Blackledge Technological University Dublin, [email protected] Follow this and additional works at: https://arrow.tudublin.ie/engscheleart2 Part of the Dynamic Systems Commons, and the Theory and Algorithms Commons Recommended Citation Blackledge, J. (2011) Cryptography and Steganography: New Algorithms and Applications. Lecture Notes, Centre for Advanced Studies, Warsaw University of Technology, Warsaw, 2011. doi:10.21427/D7ZS63 This Article is brought to you for free and open access by the School of Electrical and Electronic Engineering at ARROW@TU Dublin. It has been accepted for inclusion in Articles by an authorized administrator of ARROW@TU Dublin. For more information, please contact [email protected], [email protected], [email protected]. This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License Cryptography and Steganography: New Algorithms and Applications Prof. Dr. Jonathan Blackledge Science Foundation Ireland Stokes Professor School of Electrical Engineering Systems Dublin Institute of Technology Distinguished Professor Centre for Advanced Studies Warsaw University of Technology http://eleceng.dit.ie/blackledge http://jmblackledge.web.officelive.com [email protected] [email protected] Editor: Stanislaw Janeczko Technical editors: Malgorzata Zielinska, Anna Zubrowska General layout and cover design: Emilia Bojanczyk c Centre for Advanced Studies, Warsaw University of Technology, Warsaw 2011 For additional information on this series, visit the CAS Publications Website at http://www.csz.pw.edu.pl/index.php/en/publications ISBN: 978-83-61993-01-83 Pinted in Poland Preface Developing methods for ensuring the secure exchange of information is one of the oldest occupations in history.
    [Show full text]
  • Rhyming Dictionary
    Merriam-Webster's Rhyming Dictionary Merriam-Webster, Incorporated Springfield, Massachusetts A GENUINE MERRIAM-WEBSTER The name Webster alone is no guarantee of excellence. It is used by a number of publishers and may serve mainly to mislead an unwary buyer. Merriam-Webster™ is the name you should look for when you consider the purchase of dictionaries or other fine reference books. It carries the reputation of a company that has been publishing since 1831 and is your assurance of quality and authority. Copyright © 2002 by Merriam-Webster, Incorporated Library of Congress Cataloging-in-Publication Data Merriam-Webster's rhyming dictionary, p. cm. ISBN 0-87779-632-7 1. English language-Rhyme-Dictionaries. I. Title: Rhyming dictionary. II. Merriam-Webster, Inc. PE1519 .M47 2002 423'.l-dc21 2001052192 All rights reserved. No part of this book covered by the copyrights hereon may be reproduced or copied in any form or by any means—graphic, electronic, or mechanical, including photocopying, taping, or information storage and retrieval systems—without written permission of the publisher. Printed and bound in the United States of America 234RRD/H05040302 Explanatory Notes MERRIAM-WEBSTER's RHYMING DICTIONARY is a listing of words grouped according to the way they rhyme. The words are drawn from Merriam- Webster's Collegiate Dictionary. Though many uncommon words can be found here, many highly technical or obscure words have been omitted, as have words whose only meanings are vulgar or offensive. Rhyming sound Words in this book are gathered into entries on the basis of their rhyming sound. The rhyming sound is the last part of the word, from the vowel sound in the last stressed syllable to the end of the word.
    [Show full text]
  • Transposition Cipher in Cryptography, a Transposition Cipher Is a Method of Encryption by Which the Positions Held by Units of P
    Transposition cipher In cryptography, a transposition cipher is a method of encryption by which the positions held by units of plaintext (which are commonly characters or groups of characters) are shifted according to a regular system, so that the ciphertext constitutes a permutation of the plaintext. That is, the order of the units is changed. Mathematically a bijective function is used on the characters' positions to encrypt and an inverse function to decrypt. Following are some implementations. Contents • 1 Rail Fence cipher • 2 Route cipher • 3 Columnar transposition • 4 Double transposition • 5 Myszkowski transposition • 6 Disrupted transposition • 7 Grilles • 8 Detection and cryptanalysis • 9 Combinations • 10 Fractionation Rail Fence cipher The Rail Fence cipher is a form of transposition cipher that gets its name from the way in which it is encoded. In the rail fence cipher, the plaintext is written downwards on successive "rails" of an imaginary fence, then moving up when we get to the bottom. The message is then read off in rows. For example, using three "rails" and a message of 'WE ARE DISCOVERED. FLEE AT ONCE', the cipherer writes out: W . E . C . R . L . T . E . E . R . D . S . O . E . E . F . E . A . O . C . A . I . V . D . E . N . Then reads off: WECRL TEERD SOEEF EAOCA IVDEN (The cipherer has broken this ciphertext up into blocks of five to help avoid errors.) Route cipher In a route cipher, the plaintext is first written out in a grid of given dimensions, then read off in a pattern given in the key.
    [Show full text]
  • Substitution Cipher in Cryptography, a Substitution Cipher Is a Method Of
    Substitution cipher In cryptography, a substitution cipher is a method of encryption by which units of plaintext are replaced with ciphertext according to a regular system; the "units" may be single letters (the most common), pairs of letters, triplets of letters, mixtures of the above, and so forth. The receiver deciphers the text by performing an inverse substitution. Substitution ciphers can be compared with transposition ciphers. In a transposition cipher, the units of the plaintext are rearranged in a different and usually quite complex order, but the units themselves are left unchanged. By contrast, in a substitution cipher, the units of the plaintext are retained in the same sequence in the ciphertext, but the units themselves are altered. There are a number of different types of substitution cipher. If the cipher operates on single letters, it is termed a simple substitution cipher; a cipher that operates on larger groups of letters is termed polygraphic. A monoalphabetic cipher uses fixed substitution over the entire message, whereas a polyalphabetic cipher uses a number of substitutions at different times in the message, where a unit from the plaintext is mapped to one of several possibilities in the ciphertext and vice-versa. Contents • 1 Simple substitution o 1.1 Examples o 1.2 Security for simple substitution ciphers • 2 Homophonic substitution • 3 Polyalphabetic substitution • 4 Polygraphic substitution • 5 Mechanical substitution ciphers • 6 The one-time pad • 7 Substitution in modern cryptography • 8 Substitution ciphers in popular culture Simple substitution 1 ROT13 is a Caesar cipher, a type of substitution cipher. In ROT13, the alphabet is rotated 13 steps.
    [Show full text]
  • Trifid Ciphers
    Trifid Ciphers Trifid ciphers are examples of combination ciphers: The encryption process consists of a sequence of several different techniques. In this case substitution followed by fractionation and transposition are used in the encryption. The trifid cipher was invented by amateur cryptographer F´elix Delastelle, ca. 1900. The encryption key for a trifid cipher consists of a positive integer (the period) and a 3×3×3 array containing all of the distinct letters of the English alphabet plus one additional character. Typically, the additional character in the array is a symbol, such as a dot. The arrangement of the characters in the key array can be chosen at random. Below is the 3D example of an encryption key: A more basic way of looking at the above graph in a 2D form is by looking at the 3 layers, bottom to top, then numbering them from 1 to 3. Compare the 3D graph to the layers below. Layer 1 Layer 2 Layer 3 1 2 3 1 2 3 1 2 3 1 Y G U 1 F L K 1 . E J 2 Q O M 2 I H A 2 X P D 3 S V B 3 Z R W 3 C N T Suppose we want to encrypt the message “trick or treat” using a trifid cipher with encryption key consisting of period 4 and the above layers. i. Represent the letters in our message “trick or treat” with their coordinates in the encryption array: T R I C K O R T R E A T 333 232 221 331 213 122 232 333 232 312 223 333 Layer Row Column How to describe the position Number Number Number of the letter K on the chart.
    [Show full text]
  • 2. Classic Cryptography Methods 2.1. Spartan Scytale. One of the Oldest Known Examples Is the Spartan Scytale (Scytale /Skɪtəl
    2. Classic Cryptography Methods 2.1. Spartan scytale. One of the oldest known examples is the Spartan scytale (scytale /skɪtəli/, rhymes with Italy, a baton). From indirect evidence, the scytale was first mentioned by the Greek poet Archilochus who lived in the 7th century B.C. (over 2500 years ago). The ancient Greeks, and the Spartans in particular, are said to have used this cipher to communicate during military campaigns.Sender and recipient each had a cylinder (called a scytale) of exactly the same radius. The sender wound a narrow ribbon of parchment around his cylinder, then wrote on it lengthwise. After the ribbon is unwound, the writing could be read only by a person who had a cylinder of exactly the same circumference. The following table illustrate the idea. Imagine that each column wraps around the dowel one time, that is that the bottom of one column is followed by the top of the next column. Original message: Kill king tomorrow midnight Wrapped message: k i l l k i n g t o m o r r o w m i d n i g h t Encoded message: ktm ioi lmd lon kri irg noh gwt The key parameter in using the scytale encryption is the number of letters that can be recorded on one wrap ribbon around the dowel. Above the maximum was 3, since there are 3 rows in the wrapped meassage. The last row was padded with blank spaces before the message was encoded. We'll call this the wrap parameter. If you don't know the wrap parameter you cannot decode a message.
    [Show full text]
  • Polybius Square in Cryptography: a Brief Review of Literature
    ISSN 2278-3091 Jan Carlo T. Arroyo et al., International Journal ofVolume Advanced 9, Trends No.3, in May Computer - June Science 2020 and Engineering, 9(3), May – June 2020, 3798 – 3808 International Journal of Advanced Trends in Computer Science and Engineering Available Online at http://www.warse.org/IJATCSE/static/pdf/file/ijatcse198932020.pdf https://doi.org/10.30534/ijatcse/2020/198932020 Polybius Square in Cryptography: A Brief Review of Literature Jan Carlo T. Arroyo1, Cristina E. Dumdumaya2, Allemar Jhone P. Delima3 1,3College of Computing Education, University of Mindanao, Davao City, Davao del Sur, Philippines 1,2College of Information and Computing, University of Southeastern Philippines, Davao City, Davao del Sur, Philippines 3College of Engineering, Technology and Management, Cebu Technological University-Barili Campus, Cebu, Philippines [email protected], [email protected], [email protected] concerns data integrity, confidentiality, authentication to a ABSTRACT wireless communication system, and several other security services where information transfer between different users Cryptography is a method to secure sensitive data for storage takes place [10]–[12]. To protect the information, data are and communication in the presence of third parties called transformed into an unintelligible format using varied cipher adversaries. One of the first recorded incidents of technologies [15]. Maintaining data integrity and security is cryptography occurred in Ancient Rome, where the Polybius done through cipher whose bottleneck for an optimal cipher, also known as Polybius square, was developed. The implementation relies on the cipher used. A cipher is an Polybius cipher has been used as an advantage in winning algorithm responsible for both the encryption and decryption wars over enemies according to history and is also utilized as processes of a file being protected.
    [Show full text]
  • Certificate in E Certificate in E-Governance and Security Information System (CEGCS-04) Vernance and Cyber
    Certificate in e -Governance and Cyber Security Information System (CEGCS-04) Title Information System Adviso rs Mr. R. Thyagarajan, Head, Admn. & Finance and Acting Director, CEMCA Dr. Manas Ranjan Panigrahi, Program Officer(Education) , CEMCA Prof. Durgesh Pant, Director -SCS&IT, UOU Editor Er. Gopesh Pande, Network Engineer, Wipro Infotech, Mumbai Authors Block I> Unit I, Unit II, Unit III & Unit IV Er. Charanjeet Singh Chawla, Wing Commander, Indian Air Force, Ministry of Defence Block II> Unit I, Unit II, Unit III & Unit IV Er. Ashok Katariya, Group Captain, Indian Air Force, Ministry of Defence Block III> Unit I, Unit II, Unit III & Unit IV Er. Ashok Katariya, Group Captain, Indian Air Force, Ministry of Defence ISBN : 978 -93 -84813 -93 -2 Acknowledgement The University acknow ledges with thanks the expertixe and financial support provided by Commonwealth Educational Media Centre for Asia(CEMCA), New Delhi, for the preparation of this study material. Uttarakhand Open University, 2016 © Uttarak hand Open University, 2016. Information System is made available under a Creative Commons Attribution Share-Alike 4.0 Licence (international): http://creativecommons.org/licenses/by -sa/4.0/ It is attributed to the sources marked in the References, Article Sources and Contributors section. Published by: Uttarakhand Open University, Haldwani Expert Panel S. No. Name 1 Dr. Jeetendra Pande, School of Computer Science & IT, Uttarakhand Open University, Haldwani 2 Prof. Ashok Panjwani, Professor, MDI, Gurgoan 3 Group Captain Ashok Katariya, Ministry of Defense, New Delhi 4 Mr. Ashutosh Bahuguna, Scientist- CERT-In, Department Of Electronics & Information Technology, Government Of India 5 Mr. Sani Abhilash, Scientist- CERT-In, Department Of Electronics & Information Technology, Government Of India 6 Wing Commander C.S.
    [Show full text]
  • Computer and Data Security Class 4 ﺳﻜﻴﻨﺔ ﺣﺴﻦ هﺎﺷﻢ . د: أﺳﺘﺎذة اﻟﻤﺎدة
    Save from: www.uotechnology.edu.iq/dep‐cs Computer and Data security 4th Class أﺳﺘﺎذة اﻟﻤﺎدة: د. ﺳﻜﻴﻨﺔ ﺣﺴﻦ هﺎﺷﻢ Introduction to Data Security Basic Terminology Suppose that someone wants to send a message to a receiver, and wants to be sure that no-one else can read the message. However, there is the possibility that someone else opens the letter or hears the electronic communication. In cryptographic terminology, the message is called plaintext or cleartext. Encoding the contents of the message in such a way that hides its contents from outsiders is called encryption. The encrypted message is called the ciphertext. The process of retrieving the plaintext from the ciphertext is called decryption. Encryption and decryption usually make use of a key, and the coding method is such that decryption can be performed only by knowing the proper key. Cryptography is the art or science of keeping messages secret. Cryptanalysis is the art of breaking ciphers, i.e. retrieving the plaintext without knowing the proper key. People who do cryptography are cryptographers, and practitioners of cryptanalysis are cryptanalysts. Cryptography deals with all aspects of secure messaging, authentication, digital signatures, electronic money, and other applications. Cryptology is the branch of mathematics that studies the mathematical foundations of cryptographic methods. Basic Cryptographic Algorithms A method of encryption and decryption is called a cipher. Some cryptographic methods rely on the secrecy of the algorithms; such algorithms are only of historical interest and are not adequate for real-world needs. All modern algorithms 1 use a key to control encryption and decryption; a message can be decrypted only if the key matches the encryption key.
    [Show full text]
  • Book Cipher, Running Key Cipher, Vic Cipher and Secom Cipher
    BOOK CIPHER, RUNNING KEY CIPHER, VIC CIPHER AND SECOM CIPHER A book cipher is a cipher in which the key is some aspect of a book or other piece of text; books being common and widely available in modern times, users of book ciphers take the position that the details of the key is sufficiently well hidden from attackers in practice. This is in some ways an example of security by obscurity . It is typically essential that both correspondents not only have the same book, but the same edition .[1] Traditionally book ciphers work by replacing words in the plaintext of a message with the location of words from the book being used. In this mode, book ciphers are more properly called codes. This can have problems; if a word appears in the plaintext but not in the book, it cannot be encoded. An alternative approach which gets around this problem is to replace individual letters rather than words. One such method, used in the second Beale cipher , substitutes the first letter of a word in the book with that word's position. In this case, the book cipher is properly a cipher — specifically, a homophonic substitution cipher . However, if used often, this technique has the side effect of creating a larger ciphertext (typically 4 to 6 digits being required to encipher each letter or syllable) and increases the time and effort required to decode the message. Choosing the Key [] The main strength of a book cipher is the key. The sender and receiver of encoded messages can agree to use any book or other publication available to both of them as the key to their cipher.
    [Show full text]