Lecture
This lecture discusses two systems, Express and Tor, used for secure communication. Express focuses on hiding metadata, ensuring immunity against traffic analysis. It uses distributed point functions to send messages to two servers, maintaining constant communication cost regardless of the number of mailboxes. The system is compared to Tor, which provides anonymity but collects metadata. The lecture also covers related works like Repost and Pung, highlighting Express's performance improvements. The presentation delves into system design, security measures, and potential attacks, offering insights into the practicality and limitations of metadata-hiding communication systems.