David Stainton

I shall explain the renewed interest in mix networks. Like Tor, mix networks protect metadata by using layered encryption and routing packets between a series of independent nodes. Mix networks resist vastly more powerful adversary models than Tor though, including partial defense against global passive adversaries. In so doing, mix networks add both latency and cover traffic. I shall outline the basic components of a mix network, touch on their roles in resisting active and passive attacks, and discuss how the latency impacts reliability, application design, and user experience. In particular I'll mention how mix networks can be used with messaging applications and crypto currency to resist network surveillance and traffic analysis.

Academics have proposed various anonymity technologies with far stronger threat models than Tor, but by far the most practical and efficient option remains mix networks, which date to the founding of anonymity research by David Chaum in 1981. Tor was insp