In most networking situations, we can assume that the algorithms are known. These lecture notes describe historical encryption methods and how they are used today. 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. The encryption algorithm performs various substitutions and transformations on the plaintext. Basic vocabulary of encryption and decryption plaintext. To introduce the rudiments of the vocabulary of computer and network security and that of encryptiondecryption. Loai tawalbeh fall 2005 basic terminology plaintext the original message ciphertext the coded message. If a pair is a repeated letter, insert a filler like x, ex. Building blocks of classical encryption techniques. Cns flec03 classical encryption techniques slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Classical encryption techniques in network security 1. 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. It explains how programmers and network professionals can use cryptography to maintain the privacy of computer data.
It uses encryption algorithm to generate ciphertext that can only be read if decrypted. Introduction to network security classical encryption techniques as opposed to modern cryptography goals. Loai tawalbeh computer engineering department jordan university of science and technology jordan cpe 542. This overview includes information on how classical cryptography techniques relate to the modern day. 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.
Thisgeneralideaisillustrated in figure 1 for the case of n 4. Classical encryption techniques explained at purdue university pdf. Network security, playfair cipher, viginere cipher, classical encryption, modern encryption 1. Provides a webbased introduction to cryptography for noncs majors. 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. Help and advice for the longsuffering, overworked student. 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. If you continue browsing the site, you agree to the use of cookies on this website. The golden bough, sir james george frazer symmetric. Computer and network security by avi kak lecture3 3. 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.
Analytical study on encryption techniques and challenges. 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. Classical and modern encryption techniques are investigated and then compared here. Starting with the origins of cryptography, it moves on to explain cryptosystems, various traditional and modern. Classical encryption techniques 1 symmetric encryption substitution techniques caesar cipher monoalphabetic cipher playfair cipher hill cipher 9. Most modern systems usually use a combination of these encryption techniques along with strong implementation algorithms for increased security. This is the original intelligible message or data that is fed into the algorithm as input. This is my implementation for some classical encryption techniques. So far all the ciphers we have looked at involved only substitution.
Network encryption can be understood as the process of encrypting or encoding data and messages that are transmitted or communicated through a computer network. 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. Security issues on cryptography and network security. Network security model,cryptography,basic concepts,encryption and decryption. Lecture note 1 introduction to classical cryptography. Classical encryption techniques in cryptography and. Integrating classical encryption with modern technique. Starting with algebraic equations, this paper touches on how finite fields work and how they can be used in everyday life. Understand osi security architecture and classical encryption techniques. Classical encryption techniques there are two requirements for secure use of conventional encryption. Lawrie browns slides supplied with william stallings s book cryptography and network security. 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. Cryptography and network security for computers and email. Pdf cryptography is the art of processing data into unintelligible form without.
Classical encryption techniques jordan university of. Cryptography and network chapter 2 classical encryption. Finite fields introduction to finite fields and their applications pdf. Classical encryption techniques lecture notes on computer and network security. Network security classical encryption techniques 2. A study of encryption algorithms rsa, des, 3des and aes. 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. There are two requirements for secure use of conventional encryption. The security of playfair cipher is harder as it has 26 by 26 in total 676 diagram for frequency. Sender and receiver must have obtained copies of the secret key in a secure fashion and must keep the key secure.
Cryptography and chapter 2 classical encryption network. Classical encryption techniques in network security. Cryptography and network security pdf cns notes 2020. A substitution technique is one in which the words or text of plaintext are replaced by other letters or by numbers or symbols. Symmetric cipher model substitution techniques transposition techniques product ciphers steganography. A block cipher is one in which a block of plaintext is treated as a whole and. Pdf comparing classical encryption with modern techniques. Some basic vocabulary of computer and network security and a. The security of classical cryptography is based on the high complexity of the mathematical problem for the instance factorization of large number. Introduction to classical cryptography by noted textbook author. Introduction to classical cryptography sourav mukhopadhyay cryptography and network security ma61027. Cryptography and network security ma61027 sourav mukhopadhyay, iitkgp, 2010 5. For a symmetric encryption system to be secure, it must.
Security,history,classical cryptographic techniques. Encryption is a security method in which information is encoded in such a way that only authorized user can read it. This tutorial covers the basics of the science of cryptography. Classical encryption techniques washington university. Security, possible keys, possible ascii printable character keys per second etc. Chapter 3 classical encryption techniques cryptography. In these cryptographic algorithms, we assign numbers or algebraic elements to the given input message to be communicated between two persons.