How Cryptography Keeps You Safe

Welcome to TechTalk Education! In this video, we explore how cryptography actually works — from symmetric encryption to the powerful RSA algorithm. Whether you're new to tech or looking to solidify your understanding, this episode simplifies the math and logic behind cryptography without heavy formulas. ✅ Topics covered: What is encryption? - Symmetric vs. asymmetric cryptography - How RSA works with prime numbers - The role of public and private keys - Real-world uses: HTTPS, VPNs, messaging apps - The Extended Euclidean Algorithm (visually explained!) We use visuals, analogies, and real examples to make cryptography click for anyone — from curious learners to budding cybersecurity pros. 🔐 Perfect for: - IT students - Home-schooled learners - Security enthusiasts - Educators teaching cryptography basics - Anyone asking “What is RSA?” or “How do encryption keys work?” The No Starch Press book entitled "The Manga Guide to Cryptography" is available here: https://nostarch.com/mangacrypto 00:00 Introduction 01:05 Intro 02:27 What Is Cryptography? 02:59 Symmetric Encryption 04:05 Symmetric Encryption Uses 04:39 Caesar Cipher 05:12 Assymetric Encryption 06:30 Who Is RSA? 09:06 Use Very Large Prime Numbers 10:14 Euler's Totient Function 13:43 The Modulus 17:15 Extended Euclidian Algorithm (EEA) 19:00 Computing Private Exponent d 20:35 Dividing A Multiplicative Inverse 21:16 Euclid Division 25:07 Determining If An Inverse Exists 26:06 Backtracking Through The Previous Steps 28:00 Still Looking For The Decrypt Value d 28:56 The Result!! 29:22 Computing The Inverse 31:20 Deriving The Public & Private Keys 32:28 Decrypting the Message