[Fsfe-ie] description of Tivoisation - comments sought

[Ciaran O'Riordan]

A lawyer asked me recently how tivoisation works.  I looked around, and
there was no document explaining it.  So I've put together a description
below, but I'd like some comments on whether it's understandable and
complete enough:


===================
Tivoisation is a way of giving someone a computer whose software can
be upgraded but which will refuse to run any software that isn't first
authorised by the manufacturer.

To implement tivosiation, a hardware manufacturer must do three things:

1. Put a chip in the computer which will check any software before it
   is run and which will only allow the running of software if an
   authorised digital fingerprint is found.

2. Inject that certain digital fingerprint into each version of their
   own software.

3. Don't tell their customers the fingerprint.

By doing this, the manufacture can still publish new versions of the
software in the future.  It just has to inject the secret fingerprint
and then publish the software and users will be able to run it.

However, if the user tries to use a modified version of the software,
or tries to run some third-party software, the computer will refuse to
function fully, or will simply not run the software at all.
===================





-- 
Ciarán O'Riordan __________________ \ http://fsfeurope.org/projects/gplv3
http://ciaran.compsoc.com/ _________ \  GPLv3 and other work supported by
http://fsfe.org/fellows/ciaran/weblog \   Fellowship: http://www.fsfe.org