Master the Caesar Cipher: A Key Concept in Cryptography 🔐

Welcome to Unit-6, Lesson-1 of Number Theory, where Dr. Udar introduces the fascinating intersection of Number Theory and Cryptography through the Caesar Cipher — one of the earliest and most famous encryption techniques in history. In this lecture, you’ll understand how modular arithmetic forms the mathematical foundation of encryption and decryption processes. The Caesar Cipher is used as a perfect starting point to explore the concept of shift ciphers, encoding messages, and decoding using modular inverses. This lesson not only explains the working of Caesar Cipher but also connects it to modern cryptographic algorithms, showing how basic number theory principles still power digital security today. 📘 In This Lecture, You Will Learn: Introduction to Classical Cryptography Working principle of the Caesar Cipher Encryption and decryption using modular arithmetic Mathematical representation of cipher text and plain text Connection between number theory and modern cryptography This video is essential for students preparing for GATE, CSIR-NET, IIT JAM, Cybersecurity, and Cryptography courses, or anyone interested in the mathematical side of secure communication. 🎯 Course: Number Theory (Mathematics Major / CSIR-NET / JAM / Engineering Math) 👨‍🏫 Instructor: Dr. Udar | Simplify Math, Amplify Life