Title
Conjure: Summoning Proxies from Unused Address Space
Abstract
Refraction Networking (formerly known as "Decoy Routing") has emerged as a promising next-generation approach for circumventing Internet censorship. Rather than trying to hide individual circumvention proxy servers from censors, proxy functionality is implemented in the core of the network, at cooperating ISPs in friendly countries. Any connection that traverses these ISPs could be a conduit for the free flow of information, so censors cannot easily block access without also blocking many legitimate sites. While one Refraction scheme, TapDance, has recently been deployed at ISP-scale, it suffers from several problems: a limited number of "decoy" sites in realistic deployments, high technical complexity, and undesirable tradeoffs between performance and observability by the censor. These challenges may impede broader deployment and ultimately allow censors to block such techniques. We present Conjure, an improved Refraction Networking approach that overcomes these limitations by leveraging unused address space at deploying ISPs. Instead of using real websites as the decoy destinations for proxy connections, our scheme connects to IP addresses where no web server exists leveraging proxy functionality from the core of the network. These phantom hosts are difficult for a censor to distinguish from real ones, but can be used by clients as proxies. We define the Conjure protocol, analyze its security, and evaluate a prototype using an ISP testbed. Our results suggest that Conjure can be harder to block than TapDance, is simpler to maintain and deploy, and offers substantially better network performance.
Year
DOI
Venue
2019
10.1145/3319535.3363218
Proceedings of the 2019 ACM SIGSAC Conference on Computer and Communications Security
Keywords
Field
DocType
censorship, censorship circumvention, decoy routing, proxy, refraction networking
Address space,Internet privacy,Computer security,Computer science
Conference
ISBN
Citations 
PageRank 
978-1-4503-6747-9
1
0.37
References 
Authors
0
6
Name
Order
Citations
PageRank
Sergey Frolov111.73
Jack Wampler211.73
Sze Chuen Tan310.37
J. Alex Halderman42301149.67
Nikita Borisov52133156.58
Eric Wustrow656437.93