Hot or not: revealing hidden services by their clock skew

10 years 2 months ago
Hot or not: revealing hidden services by their clock skew
Location-hidden services, as offered by anonymity systems such as Tor, allow servers to be operated under a pseudonym. As Tor is an overlay network, servers hosting hidden services are accessible both directly and over the anonymous channel. Traffic patterns through one channel have observable effects on the other, thus allowing a service's pseudonymous identity and IP address to be linked. One proposed solution to this vulnerability is for Tor nodes to provide fixed quality of service to each connection, regardless of other traffic, thus reducing capacity but resisting such interference attacks. However, even if each connection does not influence the others, total throughput would still affect the load on the CPU, and thus its heat output. Unfortunately for anonymity, the result of temperature on clock skew can be remotely detected through observing timestamps. This attack works because existing abstract models of anonymitynetwork nodes do not take into account the inevitable im...
Steven J. Murdoch
Added 20 Aug 2010
Updated 20 Aug 2010
Type Conference
Year 2006
Where CCS
Authors Steven J. Murdoch
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