Explore a cutting-edge scalable messaging system with cryptographic privacy in this 22-minute conference talk from NSDI '20. Dive into XRD (Crossroads), a novel approach that addresses metadata leakages in end-to-end encrypted communication. Learn how XRD utilizes multiple mix networks in parallel and innovative techniques like aggregate hybrid shuffle to support millions of users while maintaining cryptographic privacy. Discover the system's architecture, deployment model, and threat analysis. Understand how XRD tackles active attacks using zero-knowledge proofs and implements chain selection for enhanced security. Examine the scalability properties of XRD, including its linear latency increase with user growth and improved performance through server expansion. Compare XRD's efficiency to other cryptographically private messaging systems like Atom and Pung. Gain insights into the implementation, setup, and overall benefits of this groundbreaking system that combines cryptographic metadata privacy with scalability. Read more