Title
Hot or not: revealing hidden services by their clock skew
Abstract
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 anonymity-network nodes do not take into account the inevitable imperfections of the hardware they run on. Furthermore, we suggest the same technique could be exploited as a classical covert channel and can even provide geolocation.
Year
DOI
Venue
2006
10.1145/1180405.1180410
ACM Conference on Computer and Communications Security
Keywords
DocType
ISBN
traffic pattern,abstract model,anonymous channel,clock skew,tor node,ip address,hidden service,classical covert channel,location-hidden service,anonymity-network node,anonymity system,covert channels,fingerprinting,security,anonymity,covert channel,overlay network,temperature
Conference
1-59593-518-5
Citations 
PageRank 
References 
78
5.62
24
Authors
1
Name
Order
Citations
PageRank
Steven J. Murdoch180657.90