Cryptography: Caesar's Cipher

This lecture explores the history of cryptography, focusing on Caesar's Cipher, a simple encryption method that shifts each letter by a fixed number of positions. The instructor explains how this method can be easily decrypted using brute force, leading to the introduction of more secure encryption techniques like letter permutations and frequency analysis. The lecture delves into the concept of frequency analysis, where the average occurrence of letters in a language is used to crack encrypted messages. The instructor also highlights the limitations of frequency analysis in decrypting short messages and traces the origins of this cryptographic technique back to Alkindi, an ancient scholar.