Welcome to "V5b: Authenticated Encryption: AES-GCM Galois Counter Mode," a critical lecture in Alfred Menezes's "Crypto 101: Building Blocks" course. In this video, we dive into the inner workings of AES-GCM (Galois Counter Mode), one of the most widely-used encryption schemes globally, employed in securing everything from web traffic to financial transactions. Perfect for computer science students, software engineers, mathematicians, applied cryptographers, and cybersecurity professionals, this lecture offers an in-depth explanation of AES-GCM's core features, focusing on its use of multiplications in Galois fields and the CTR (Counter) mode of encryption. Learn how AES-GCM ensures both confidentiality and integrity by providing authenticated encryption, making it a robust choice for modern cryptography. We also introduce GMAC (Galois Message Authentication Code), which is a crucial part of this mode for message authentication. You'll gain insights into the dangers of reusing initialization vectors (IVs), a critical aspect of ensuring security. We cover AES-GCM’s efficiency in encryption and its role in balancing security and performance. Whether you’re studying cryptography or working in security, this video provides essential knowledge on one of today’s most powerful encryption schemes. Enhance your expertise with this state-of-the-art, free online cryptography course! Lecture playlist: Course web page: The slides are available on the course web page. Other cryptography courses: Slides 00:00 Introduction 00:21 Slide 195: Overview 00:52 Slide 196: CTR: CounTeR mode of encryption 03:50 Slide 197: Notes on CTR mode 05:20 Slide 198: Multiplying blocks 07:14 Slide 199: Galois Message Authentication Code (GMAC) 10:03 Slide 200: Computing f_A(H) using Horner's rule 11:08 Slide 201: Security argument 12:52 Slide 202: Authenticated encryption: AES-GCM 14:22 Slide 203: AES-GCM encryption/authentication 16:16 Slide 204: AES-GCM decryption/authentication 17:11 Slide 205: Some features of AES-GCM 18:38 Slide 206: Performance 18:58 Slide 207: IV's should not be repeated 21:56 Coming up