[2557] in cryptography@c2.net mail archive
Re: Position escrow
daemon@ATHENA.MIT.EDU (Phil Karn)
Wed Apr 22 12:48:16 1998
Date: Tue, 21 Apr 1998 18:16:49 -0700 (PDT)
From: Phil Karn <karn@Qualcomm.com>
To: shamrock@netcom.com
CC: cryptography@c2.net, cypherpunks@toad.com, karn@Qualcomm.com
In-reply-to: <Pine.SUN.3.91.980421153643.2922A-100000@netcom5> (message from Lucky Green on Tue, 21 Apr 1998 16:43:38 -0700 (PDT))
Well, given that I work in CDMA, and given that CDMA provides some
inherent positioning capabilities, the possibility of defeating
positioning by hacking the phone software to "dither" the return link
signal timing has occurred to me. It wouldn't let you appear to be in
a different cell than the one you're in, but it would certainly
decrease the measurement precision. You could disable the dither if
you want when you make an E911 call.
What sweet revenge that would be against the government that inflicted
Selective Availability on all us civilian GPS users. :-)
Phil
