Explore the security implications of multiplexing data streams in TLS 1.3's record layer through this 21-minute conference talk. Delve into the study of secure stream-based channels, focusing on the essential feature of multiplexing multiple data streams over a single channel in real-world protocols like TLS. Examine the model, attack cycle, and evolution of the proposed approach, while addressing challenges in the record layer. Gain insights into record layer composition and the associated proof. Conclude with a comprehensive understanding of partially specified channels and their impact on TLS 1.3 security.