How the Vigenère Cipher Works

In this video, we dive into the fascinating world of classical cryptography to explore the Vigenère cipher — once considered unbreakable. We'll uncover how it works, how it's encrypted and decrypted, and why longer keys increase its strength — until clever analysis methods cracked it wide open. 📌 What You’ll Learn: ✅ How the Vigenère cipher encrypts/decrypts messages using a repeating key. ✅ Why longer keys create more secure ciphertext (frequency flattening). ✅ How Kasiski Examination & Index of Coincidence break the cipher — even without the key. ✅ Visual breakdowns of letter frequency distributions and key-based encryption steps. 🎥 Animated with Manim: Making cryptography clear, visual, and beautiful. 🔗 Manim Community: https://www.manim.community/ 💡 Love ciphers, math, or codebreaking history? Like, subscribe, and hit the bell (🔔) for more visual cryptography content! 📌 Video Chapters: 0:00 - Introduction 0:26 - Alice & Bob Communication 1:08 - Encryption Process 3:05 - Decryption Process 4:49 - Vigenère Table Encryption 6:10 - Vigenère Table Decryption 6:45 - Security of the Cipher 7:59 - Conclusion 🎵 Background Music: "Calm Evening – Relaxing Neoclassical Piano" (Royalty-Free via Pixabay, used under their Content License). 🔗 Source: [Pixabay Link] | License: [Pixabay License Summary] 🎨 Icons by Flat Icons, juicy_fish, and Smashicons from Flaticon (www.flaticon.com). 🔖 Tags: #vigenere #cryptography #cipher #codebreaking #manim #mathanimation