If you continue browsing the site, you agree to the use of cookies on this website. The secret key is also input to the encryption algorithm. Classical encryption techniques 1 symmetrickey algorithms are algorithms for cryptography that use the same cryptographic keys for both encryption of plaintext and decryption of ciphertext. Network security chapter 2 fifth edition by william stallings lecture slides by lawrie brown with edits by rhb chapter 2 classical encryption techniques i am fairly familiar with all the forms of secret writings, and am myself the author of a trifling monograph upon the subject, in which i analyze one hundred and sixty separate. Loai tawalbeh computer engineering department jordan university of science and technology jordan cpe 542. A block cipher is one in which a block of plaintext is treated as a whole and. For a symmetric encryption system to be secure, it must. The encryption algorithm performs various substitutions and transformations on the plaintext. Finite fields introduction to finite fields and their applications pdf. Building blocks of classical encryption techniques. Encryption is a security method in which information is encoded in such a way that only authorized user can read it. Cryptography and network security for computers and email. It uses encryption algorithm to generate ciphertext that can only be read if decrypted. A substitution technique is one in which the words or text of plaintext are replaced by other letters or by numbers or symbols.
Loai tawalbeh fall 2005 basic terminology plaintext the original message ciphertext the coded message. Classical encryption techniques lecture notes on computer and network security. Integrating classical encryption with modern technique. Symmetric cipher model substitution techniques transposition techniques product ciphers steganography. Classical encryption techniques in cryptography and.
To introduce the rudiments of the vocabulary of computer and network security and that of encryptiondecryption. Network security model,cryptography,basic concepts,encryption and decryption. Help and advice for the longsuffering, overworked student. Communication encrypts as com x munication if the letters appear on the same row of your table, replace them with the letters to their immediate right respectively wrapping around to the left side of the row if a letter in the original pair was on the right side of the row. Network security chapter 2 chapter 2 classical encryption techniques many savages at the present day regard their names as vital parts of themselves, and therefore take great pains to conceal their real names, lest these should give to evildisposed persons a handle by which to injure their owners. Pdf comparing classical encryption with modern techniques. These lecture notes describe historical encryption methods and how they are used today. Introduction to classical cryptography by noted textbook author. Basic vocabulary of encryption and decryption plaintext. The golden bough, sir james george frazer symmetric. Computer network security keywords symmetric cipher model, some basic terminology, cryptography classification, cryptanalysis, substitution, substitution.
If a pair is a repeated letter, insert a filler like x, ex. Cryptograph y and network security seventh edition by william stallings chapter 3 classical. In most networking situations, we can assume that the algorithms are known. This tutorial covers the basics of the science of cryptography. Network encryption can be understood as the process of encrypting or encoding data and messages that are transmitted or communicated through a computer network. Pdf cryptography is the art of processing data into unintelligible form without.
Cryptography and network security chapter 2 fifth edition by william stallings lecture slides by lawrie brown chapter 2 classical encryption techniques i am fairly familiar with all the forms of secret writings, and am myself the author of a trifling monograph upon. Starting with the origins of cryptography, it moves on to explain cryptosystems, various traditional and modern. Thisgeneralideaisillustrated in figure 1 for the case of n 4. Classical encryption techniques there are two requirements for secure use of conventional encryption. A study of encryption algorithms rsa, des, 3des and aes.
This is the original intelligible message or data that is fed into the algorithm as input. This overview includes information on how classical cryptography techniques relate to the modern day. This is my implementation for some classical encryption techniques. The security of playfair cipher is harder as it has 26 by 26 in total 676 diagram for frequency. Classical and modern encryption techniques are investigated and then compared here. In this chapter, we shall cover some of the basic cryptographic algorithms that were used for providing a secure way of communicating the messages from one person to another person in the olden days. Another way of classifying cryptographic algorithm are mono alphabetic cipher and poly alphabetic cipher 22 based on the mapping of plain text alphabet to cipher text alphabet. Security, possible keys, possible ascii printable character keys per second etc. Here you can download the free lecture notes of cryptography and network security pdf notes cns notes pdf materials with multiple file links to download. In addition to security, these systems also provide numerous additional benefits, such as verification of user identity, and ensuring that the received data cannot be tampered with. Provides a webbased introduction to cryptography for noncs majors. Cryptography and network security pdf cns notes 2020. Starting with algebraic equations, this paper touches on how finite fields work and how they can be used in everyday life. Classical encryption techniques washington university.
Classical encryption techniques in network security 1. Fundamental concepts of encryption techniques are discussed. Most modern systems usually use a combination of these encryption techniques along with strong implementation algorithms for increased security. Classical encryption techniques explained at purdue university pdf. There are two requirements for secure use of conventional encryption.
If the plaintext is viewed as a sequence of bits, then substitution method comes into picture which involves replacing plaintext bit patterns with cipher text bit patterns. Classical encryption techniques in network security. Analytical study on encryption techniques and challenges. Introduction to network security classical encryption techniques as opposed to modern cryptography goals. Security issues on cryptography and network security. Classical encryption techniques 1 symmetric encryption substitution techniques caesar cipher monoalphabetic cipher playfair cipher hill cipher 9. In these cryptographic algorithms, we assign numbers or algebraic elements to the given input message to be communicated between two persons.
Lawrie browns slides supplied with william stallings s book cryptography and network security. There are two types of encryptions schemes as listed below. Network security, playfair cipher, viginere cipher, classical encryption, modern encryption 1. The security of classical cryptography is based on the high complexity of the mathematical problem for the instance factorization of large number. Cryptography and chapter 2 classical encryption network. Chapter 3 classical encryption techniques cryptography. Computer and network security by avi kak lecture3 3. Cryptography and network chapter 2 classical encryption. So far all the ciphers we have looked at involved only substitution. Understand osi security architecture and classical encryption techniques. Sender and receiver must have obtained copies of the secret key in a secure fashion and must keep the key secure. Lecture note 1 introduction to classical cryptography.
1118 112 213 867 1121 1438 757 594 1532 797 395 1520 131 1393 61 406 512 1163 691 285 791 21 1660 1296 901 1663 124 968 995 1569 1039 788 147 1619 1003 847 948 593 591 827 1244 1344