VIGENERE CIPHER LESSON 7 |Polyalphabetic cipher|Cryptography& network security| Information security

JFULL CRYPTOGRAPHY AND NETWORK SECURITY LECTURES PLAYLIST: https://youtube.com/playlist?list=PLCgLCvfziuGaUzar6eyMq_4958c8Bbnhw #vigenerecipher #classicalencryptiontechniques Our telegram channel link: https://t.me/shashikschannel Link for our channel telegram group for CSE ISE IT: https://t.me/+AyU4RtrVE-82Njc1 Hi All, Welcome to the Channel!! Hope you find the video useful. If Yes ,Do like the Video and shower some positivity. Thanks for supporting me by SUBSCRIBING to the Channel .. Do press the "BELL icon" to get instant notifications when I upload new videos/updates.Stay Connected... Join this channel to get access to perks: https://www.youtube.com/channel/UCYTShEnB7tKh4s0f071edyQ/join CNS LESSON -5 https://youtu.be/G0XKet4-m8o CNS LESSON 6: https://youtu.be/p0NmV3Vt9CA CNS LESSON-4 CAESAR CIHER,PLAYFAIR CIPHER https://youtu.be/JnNZXxHEUR0 CNS LESSON-3 SYMMETRIC CIPHER MODEL,CHARACTERISTICS OF CRYPTOGRAPHIC SYSTEMS,CRYPTANALYTIC ATTACKS: https://youtu.be/iWthhpNa3r4 CNS LESSON -2 SECURITY ATTACKS,SERVICES,MECHANISMS https://youtu.be/ymJh86z6Ztg CNS LESSON-1 INTRODUCTION,COMPUTER,NETWORK,INTERNET SECURITY,OSI SECURITY ARCHITECTURE https://youtu.be/XdZEaWVN_OM #cryptographyandnetworksecurity #hillcipher #hillcipherencryption #hillcipherdecryption #cnslectures #computernetworks #networksecurity Classical encryption techniques help us to illustrate the basic approaches for symmetric encryption used today and the types of cryptanalytic attacks that must be anticipated. The two Basic building blocks of all encryption technique are substitution and transposition. In this video We explore the classical substitution techniques of caesar cipher,mono aplhabetic cipher and playfair cipher. A substitution technique is one in which the letters of plaintext are replaced by other letters or by numbers or symbols. If the plaintext is viewed as a sequence of bits, then substitution involves replacing plaintext bit patterns with ciphertext bit patterns. Caesar cipher replaces each letter by a letter standing three places further down the alphabet. We have Caesar cipher as: c = E(k, p) = (p + k) mod (26) p = D(k, c) = (c – k) mod (26) Mono alphabetic ciphers allows an arbitrary substitution, where the translation alphabet can be any permutation of the 26 alphabetic characters. Each plaintext letter maps to a different random cipher text letter,hence key is 26 letters long The best-known multiple-letter encryption cipher is the Playfair, which treats digrams in the plaintext as single units and translates these units into ciphertext digrams In playfair cipher , Plaintext is encrypted two letters at a time 1.If a pair is a repeated letter, insert filler like 'X’ 2.If both letters fall in the same row, replace each with letter to right (wrapping back to start from end) 3.If both letters fall in the same column, replace each with the letter below it (wrapping to top from bottom) 4.Otherwise each letter is replaced by the letter in the same row and in the column of the other letter of the pair #Playfaircipher #Caesarcipher #monoalphabeticcipher #informationsecurity #annauniversityCNSCryptographyandnetworksecurity #VTUCryptography #cnslectures