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Title: Padding-only Defenses Add Delay in Tor
Website fingerprinting is an attack that uses size and timing characteristics of encrypted downloads to identify targeted websites. Since this can defeat the privacy goals of anonymity networks such as Tor, many algorithms to defend against this attack in Tor have been proposed in the literature. These algorithms typically consist of some combination of the injection of dummy "padding'' packets with the delay of actual packets to disrupt timing patterns. For usability reasons, Tor is intended to provide low latency; as such, many authors focus on padding-only defenses in the belief that they are "zero-delay.'' We demonstrate through Shadow simulations that by increasing queue lengths, padding-only defenses add delay when deployed network-wide, so they should not be considered "zero-delay.'' We further argue that future defenses should also be evaluated using network-wide deployment simulations.  more » « less
Award ID(s):
1815757
NSF-PAR ID:
10457335
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
WPES'22: Proceedings of the 21st Workshop on Privacy in the Electronic Society
Volume:
21
Page Range / eLocation ID:
29 to 33
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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