Uwe Klein <uwe_klein_habertw...@t-online.de> wrote: > j...@specsol.spam.sux.com wrote: >> Richard B. Gilbert <rgilber...@comcast.net> wrote: > >>>Didn't I just see an announcement that GPS was going to be jammed in >>>order to test something or other? >> >> >> Yeah, it happens quite often on a scheduled basis in limited areas. >> > Hmm, it should not be all that difficult to set up a limited reach > GPS WAAS/EGNOS impostor. >> > elsewher: > Bruce Schneier ( security guy ): > http://www.schneier.com/blog/archives/2008/09/gps_spoofing.html > > > uwe
OK, so the bad guy sets up the stuff for a GPS spoofer and parks it next to the targeted building where high dollar value stuff goes on in hopes of tweeking their system clocks and stealing a fortune. First issue; a big bucks operation is likely in a multi-story building with the GPS antenna on the roof and GPS antennas have low sensitivity looking down. Our bad guys just happen to know something about antenna patterns, so they obtained some high power RF amplifiers to make sure their signal dominates. So, after carefully syncing their spoofer to the real time, because if they don't, the time jump will just be rejected, the bad guys start cranking up the output power until their signal dominates. At that point they start slowly changing the time to something else. Meanwhile, inside the building where NTP was set up by someone with a clue that bothered to read the documentation, the target client computers notice that the GPS source is different than all the other sources and decide the GPS source has failed and ignore the GPS data. Drat that NTP voting alogorithm. -- Jim Pennino Remove .spam.sux to reply. _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions