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: cypherpunks at lne.com
> > From: Peter Wayner <pcw2 at flyzone.com>
> > Subject: Searching for uncopyable key made of sparkles in plastic
> > Sender: owner-cypherpunks at lne.com
> >
> > 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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Ronald L. Rivest
Room 324, 200 Technology Square, Cambridge MA 02139
Tel 617-253-5880, Fax 617-258-9738, Email <rivest at mit.edu>


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