Some details from a 1996 paper: http://www.cs.georgetown.edu/~denning/infosec/Grounding.txt
-Declan On Mon, Nov 26, 2001 at 11:35:51AM -0500, Trei, Peter wrote: > Curious. 4-5 years ago Denning and another associate (I > forget who, it's in the archives :-) tried to market an authentication > scheme which purported to authenticate the location of a remote > user using GPS.
