Explore the evolution of secure group messaging in this 51-minute Black Hat conference talk. Gain insights into message encryption protocols and understand the current ecosystem, including challenges in corporate settings. Learn why personal messaging systems have adopted Signal while corporate messaging faces scalability issues. Discover the Messaging Layer Security (MLS) protocol, comparing it to TLS and examining its key components like binary trees and pairwise operations. Delve into metadata considerations, liability concerns, and delivery services. Understand the implications for business messaging and get a comprehensive overview of the future of secure group communication.