MultiFlow: Cross-Connection Decoy Routing using TLS 1.3 Session Resumption


Victoria Manfredi and Pi Songkuntham, Wesleyan University


Most approaches to circumventing Internet censorship and monitoring use conventional proxies which are accessed directly by their IP addresses and so are easily blocked. Decoy routing is an alternative approach that deploys a proxy in association with a router, called a decoy router, that is only accessible indirectly when traffic traverses the router. In this work, we design MultiFlow, a new decoy routing protocol that re-uses the TLS protocol's session resumption mechanism to enable the decoy router itself to resume a client's session. As a consequence, MultiFlow is able to (1) authenticate a client without blocking traffic inline on the decoy router, and (2) use information provided by the client to bootstrap the establishment of additional secure connections for covert communication. The client and decoy router then use a message board-like tunnel to communicate across multiple connections in a way that mitigates probing and traffic analysis attacks.

Open Access Media

USENIX is committed to Open Access to the research presented at our events. Papers and proceedings are freely available to everyone once the event begins. Any video, audio, and/or slides that are posted after the event are also free and open to everyone. Support USENIX and our commitment to Open Access.

@inproceedings {220209,
author = {Victoria Manfredi and Pi Songkuntham},
title = {{MultiFlow}: {Cross-Connection} Decoy Routing using {TLS} 1.3 Session Resumption},
booktitle = {8th USENIX Workshop on Free and Open Communications on the Internet (FOCI 18)},
year = {2018},
address = {Baltimore, MD},
url = {},
publisher = {USENIX Association},
month = aug