"Back in 2005, the same NSA inventor, Michael Reifer, and a colleague were granted a patent called 'Method for Geolocating Logical Network Addresses'... It was a technique for matching IP addresses to physical geographical locations, based solely on packet timing information. One hurdle for geolocating IP addresses using this technique is that content filters, firewalls and other devices can add to the latency time of a route, thus skewing the results and diminishing the accuracy. Furthermore, attackers could intercept and retransmit traffic, also skewing results. To effectively geolocate an IP address, the NSA would need more information about the devices on the path.
"Enter last week's patent by the same inventor, 'Method of detecting an intermediary communication device,' (Michael Reifer). This new patent is built on the same general technique- it uses timing information alone to detect stepping stones on a path, and identify their functions. Using this second patent in conjunction with the first, the NSA could track Internet users with better accuracy, and also maintain an increasingly comprehensive map of Internet topology and devices."
Slashdot Mirror
"Back in 2005, the same NSA inventor, Michael Reifer, and a colleague were granted a patent called 'Method for Geolocating Logical Network Addresses'... It was a technique for matching IP addresses to physical geographical locations, based solely on packet timing information. One hurdle for geolocating IP addresses using this technique is that content filters, firewalls and other devices can add to the latency time of a route, thus skewing the results and diminishing the accuracy. Furthermore, attackers could intercept and retransmit traffic, also skewing results. To effectively geolocate an IP address, the NSA would need more information about the devices on the path.
"Enter last week's patent by the same inventor, 'Method of detecting an intermediary communication device,' (Michael Reifer). This new patent is built on the same general technique- it uses timing information alone to detect stepping stones on a path, and identify their functions. Using this second patent in conjunction with the first, the NSA could track Internet users with better accuracy, and also maintain an increasingly comprehensive map of Internet topology and devices."
http://philosecurity.org/2008/12/29/nsa-another-blow-against-internet-anonymity