@inproceedings{14c6642491c249ebb961fd116c738d59,
title = "Analyzing an adaptive reputation metric for anonymity systems",
abstract = "Low-latency anonymity systems such as Tor rely on intermediate relays to forward user traffic; these relays, however, are often unreliable, resulting in a degraded user experience. Worse yet, malicious relays may introduce deliberate failures in a strategic manner in order to increase their chance of compromising anonymity. In this paper we propose using a reputation metric that can profile the reliability of relays in an anonymity system based on users' past experience. The two main challenges in building a reputation-based system for an anonymity system are: first, malicious participants can strategically oscillate between good and malicious nature to evade detection, and second, an observed failure in an anonymous communication cannot be uniquely attributed to a single relay. Our proposed framework addresses the former challenge by using a proportional-integral-derivative (PID) controller-based reputation metric that ensures malicious relays adopting time-varying strategic behavior obtain low reputation scores over time, and the latter by introducing a filtering scheme based on the evaluated reputation score to effectively discard relays mounting attacks. We collect data from the live Tor network and perform simulations to validate the proposed reputation-based filtering scheme. We show that an attacker does not gain any significant benefit by performing deliberate failures in the presence of the proposed reputation framework.",
keywords = "Anonymity, Pid controller., Reputation model, Tor network",
author = "Anupam Das and Nikita Borisov and Matthew Caesar",
year = "2014",
doi = "10.1145/2600176.2600187",
language = "English (US)",
isbn = "9781450329071",
series = "ACM International Conference Proceeding Series",
publisher = "Association for Computing Machinery",
booktitle = "Proceedings of the 2014 Symposium and Bootcamp on the Science of Security, HotSoS 2014",
address = "United States",
note = "2014 Symposium and Bootcamp on the Science of Security, HotSoS 2014 ; Conference date: 08-04-2014 Through 09-04-2014",
}