On Sat, Apr 2, 2011 at 4:15 AM, Kevin W. Wall <kevin.w.w...@gmail.com> wrote: > On 04/02/2011 04:10 AM, Jeffrey Walton wrote: >> Hi Guys, >> >> Given a mobile device with GPS location data available, is there any >> benefit to using the location data as an entropy source? >> >> I'm wondering how useful GPS coordinates are if an adversary can >> determine location by triangulating a carrier's cell tower data. > > Over some duration (assuming said GPS is on the move) or just at > some single fixed point in time? Could be either.
> At most, I would think you'd only be able to collect a few bits. Agreed. I was going to pass the bits through a hash/cipher in an effort to extract any entropy, and then send it into a PRNG. > And I would think an adversary who has observed your travel patterns > might be able to exploit just about anything if your movements > are more or less predictable. Right - suppose the travel patterns were deduced from cell tower triangulation. Is it a moot point to use GPS coordinates as a [low entropy] source? (I'm side stepping a 'physical tail'). Jeff _______________________________________________ cryptography mailing list cryptography@randombit.net http://lists.randombit.net/mailman/listinfo/cryptography
