> > On the problem of distributing a new hex image: with a few checks &
> > procedures you could distrubute the XOR of the old and the new image.
> > Cryptographically this is (almost?) equal to the 'one time pad', the
> > strongest possible cypher. Of course this requires that the loader can
read
> > the old content....
>
> (snip comments from BAJ)
>

I was not addressing that issue, but a related point: once you have a secure
chip (bootloader, ICSP disabled), how do you distribute a new version of
your application without giving the 'customer' the ability to get access to
the actual code? The answer that I gave is: just distribute the XOR of the
old and the new application.

Wouter

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