>Why should a pdf be locked? Getting away from the idea that work is always
>on paper says to me that it should not be read-only *at the user end*. The
>emerging means of authentication described by Adrian should be an excellent
>way forward, but why the need to lock as well?
>
>I ask because for projects such as ours, which involves adding third-party
>reference links to pdf documents, locking is not insurmountable but is
>against the principle of what we are trying to demonstrate.
I prefer to use the term "signed". This authenticates the document
(or a fragment of it) but does not prevent others from "re-using"
it (although the original signature is now invalidated if they do
quote it with changes).
A document can be signed many times by many people of course.
I am convinced that as we move into an "information anywhere and
from anywhere" era, the need to know which bit came from where
and when becomes essential.
--
Henry Rzepa. +44 (0)20 7594 5774 (Office) +44 (0)20 7594 5804 (Fax)
Dept. Chemistry, Imperial College, London, SW7 2AY, UK.
http://www.ch.ic.ac.uk/rzepa/
Received on Mon Jan 24 2000 - 19:17:43 GMT