High-speed Anonymous Communication

Project Description

This project considers the scalability issues of current-generation anonymous networks such as Tor. By requiring relays to keep state for each anonymous connection, Tor suffers from scalability limitations. We are designing next-generation anonymous networks that provide anonymity features as part of their default routing architecture. By leveraging source-selected routing architectures such as SCION, we can offer highly scalable and highly efficient end-to-end anonymous routing that does not need to keep per-flow state on routers. Our initial experiments show that this design scales to millions of nodes and can forward traffic at near line-rate.

HORNET: High-speed Onion Routing at the Network Layer

HORNET is a system that enables high-speed end-to-end anonymous channels by leveraging next-generation network architectures. HORNET is designed as a low-latency onion routing system that operates at the network layer thus enabling a wide range of applications. It uses only symmetric cryptography for data forwarding yet requires no per-flow state on intermediate routers. This design enables HORNET routers implemented on off-the-shelf hardware to process anonymous traffic at over 93 Gb/s. HORNET is also highly scalable, adding minimal processing overhead per additional anonymous channel.

The Security Now podcast discussed problems with Tor and how HORNET can help. Coverage begins at 1:31:35, but be sure to watch until 1:55:00!


HORNET has been covered in the press: Ars Technica, BBC, Engadget, VICE, The Register.

Project Participants

Chen Chen, Daniele E. Asoni, David Barrera, Adrian Perrig. In collaboration with George Danezis



HORNET: High-speed Onion Routing at the Network Layer 
Chen Chen, Daniele E. Asoni, David Barrera, George Danezis, Adrian Perrig.
In Proceedings of the ACM Conference on Computer and Communications Security (CCS) 2015.
Research Area: High-speed Anonymous Communication