It's an interesting idea, but I think the problem is going to be that it either becomes predictable, and/or problematic. If you know where the computer comes from or where it would be used, you know the key, and it's not hard to feed fake data in. You're also working with a relatively limited subset of the entropy space (I just made that I up) unless you get really granular on the coordinates, in which case you need a good, reliable signal to make sure the GPS coordinates are stable. You also have the issue of only being able to unencrypt the device at a specific location (i.e. I take my laptop to Starbucks to work and now can't get it to boot), or you have to know the GPS coordinates of where you're going and you have to be able to program in multiple keys.
However, it would be pretty awesome if you combined positional cryptography with traditional, in the sense that you could set a different password based on location. I.e. a 6 character password for at home, 10 for at work, 15 for at Starbucks and a 64 character password for anywhere else.
It's an interesting idea, but I think the problem is going to be that it either becomes predictable, and/or problematic. If you know where the computer comes from or where it would be used, you know the key, and it's not hard to feed fake data in. You're also working with a relatively limited subset of the entropy space (I just made that I up) unless you get really granular on the coordinates, in which case you need a good, reliable signal to make sure the GPS coordinates are stable. You also have the issue of only being able to unencrypt the device at a specific location (i.e. I take my laptop to Starbucks to work and now can't get it to boot), or you have to know the GPS coordinates of where you're going and you have to be able to program in multiple keys.
However, it would be pretty awesome if you combined positional cryptography with traditional, in the sense that you could set a different password based on location. I.e. a 6 character password for at home, 10 for at work, 15 for at Starbucks and a 64 character password for anywhere else.