Explore the new TLS extension Encrypted Client Hello (ECH) in this comprehensive video lecture. Learn about the mechanism to encrypt the entire client hello, its elegant design, and potential limitations. Dive into topics such as classic TLS with SNI, ESNI, and ECH implementation. Understand the process of preparing TLS ECH, building outer and inner client hellos, and server-side decryption attempts. Examine the challenges of backend management, larger client hellos, and potential issues with multiple domains on a single IP address. Gain insights into the intricacies of ECH and its impact on TLS handshake security.