Improving Anonymity using Social Links
Krishna P. N. Puttaswamy
Alessandra Sala
Ben Y. Zhao
IEEE International Workshop on Secure Network Protocols (NPSec 2008)
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Paper Abstract
Protecting user privacy in network communication is vital in today's
open networking environment. Current anonymous routing protocols provide
anonymity by forwarding traffic through a static path of randomly
selected relay nodes. In practice, however, malicious relays can
perform passive logging attacks to compromise the anonymity of a flow.
This degradation is accelerated when nodes fail, forcing source node to
reconstruct a path, and in doing so, leaking more information to passive
loggers. This "predecessor attack" is highly effective and difficult to
defend against on current systems. In this paper, we propose a highly
effective approach to blocking predecessor attacks by leveraging trusted
links from social networks. We first show how users can completely
shield themselves from traditional logging attacks. We then propose a
hybrid logging attack optimized for social networks, and perform
detailed analysis to show that we can defend against it using optimized
path selection techniques. Finally, we analyze detailed measurement
traces from Facebook to show that our approach is indeed feasible given
the user behavior in social networks today.