Re: Searching for uncopyable key made of sparkles in plastic

[Ronald L. Rivest]

See the references by Pappu and Devadas
for lecture 18 of my class:
   http://theory.lcs.mit.edu/classes/6.857/lecture.html
        Cheers,
        Ron
At 06:44 PM 12/4/2003, Peter Fairbrother wrote:
R. A. Hettinga wrote:

>
> --- begin forwarded text
>
>
> Status:  U
> Date: Tue, 2 Sep 2003 14:45:43 -0400
> To: [EMAIL PROTECTED]
> From: Peter Wayner <[EMAIL PROTECTED]>
> Subject: Searching for uncopyable key made of sparkles in plastic
> Sender: [EMAIL PROTECTED]
>
> Several months ago, I read about someone who was making a key that
> was difficult if not "impossible" to copy. They mixed sparkly things
> into a plastic resin and let them set. A camera would take a picture
> of the object and pass the location of the sparkly parts through a
> hash function to produce the numerical key represented by this hunk
> of plastic. That numerical value would unlock documents.
>
> This was thought to be very difficult to copy because the sparkly
> items were arranged at random. Arranging all of the sparkly parts in
> the right sequence and position was thought to be beyond the limits
> of precision for humans.
>
> Can anyone give me a reference to this paper/project?
>
>
> Thanks!
>
> -Peter
(catching up on old posts)

Not a ref as such, more a bit of trivia.

A similar system was used to verify SALT. Russian ICBM's etc had sparkles
glued to them, and from time to time US people would test them to see if
they were the same missiles.
I don't know what the Russians did to the US missiles, but I think it was
the same.
-- Peter Fairbrother

I hear that the emperor of china
used to wear iron shoes with ease
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