Курс по криптографии — Шифр Плэйфера

Cryptography Course in Farzin Academy:    • Cryptography Course - Introduction   In this Farzin Academy video, we explore the Playfair Cipher, a classical encryption technique that encrypts text in pairs of letters instead of encrypting each letter individually. 🔐 You'll learn how to construct the Playfair 5×5 key table, encrypt and decrypt messages using the Playfair rules, and understand how the cipher can be attacked using digraph (diagram) frequency analysis. The lecture includes step-by-step examples of both encryption and decryption. 🧠 Key Topics Covered: Introduction to the Playfair Cipher Constructing the 5×5 Playfair table Combining I and J in the same cell Dividing plaintext into pairs Playfair encryption rules Same-row and same-column cases Rectangle rule Encrypting a message using Playfair Decrypting Playfair ciphertext Breaking the Playfair Cipher Digraph frequency analysis Practical cryptanalysis example 🎯 Perfect for cybersecurity and computer science students, cryptography learners, and anyone interested in classical encryption and cryptanalysis. 👉 Subscribe to Farzin Academy for more Cryptography, Cybersecurity, Artificial Intelligence, Databases, and Computer Science tutorials! This lecture covers the Playfair Cipher, its encryption and decryption rules, the 5×5 key table, and breaking the cipher using digraph frequency analysis.