<i>The cables indicate that the American government has been fighting a pitched battle with intruders who have been clearly identified as using Chinese-language keyboards and physically located in China.</i><p>Does anyone have insight into how keyboard language and physical location get clearly identified? I can't think of how you'd do that reliably.<p>Keyboard language: can you build timing signatures for how people type on different keyboards? Then set up a keylogger on a known compromised host or a honeypot, watch the intruder type for a while, and match the signature? That seems pretty easily defeatable: do as much as you can via scripts, and if you ever need to type something, pass all your keystrokes through a filter that knows how to mimic each timing signature.<p>I can't come up with a plausible way to pin down physical location, but I'm sure someone on here has a better working knowledge of that kind of thing than I do.