[cap-talk] Delegation/Proxy equivalence and limited lifespan objects?

Rob Meijer capibara at xs4all.nl
Mon Nov 12 08:28:25 EST 2007

When trying to defend that proxying and delegation of permissions would
be equivalent from a authority point of view, the folowing was brought
as an argument against delegation:

If Alice delegates a permission to Bob and Bob re-delegates it to Carol,
the equivalence seems to only apply if Bob has an unlimited lifetime.
One could argue that Alice could use a caretaker and revoke the authority
at any time, but this still would not fall into sync with the end of life
event of the Bob object. I could imagine that it may be possible to
construct a caretaker like pattern that would allow Alice to remain
oblivious to the end of life of Bob, but would revoke Carol her authority
at the moment that the end of life occurs for Bob, so that equivalence
could still be shown. It woulf appear that such a pattern would be needed
for the 'can always proxy' stand to hold with limited lifetime objects.

Has any work been done on patterns like this? and does anyone know if there
are any conclusive results with respect to equivalence possibilities with
limited lefespan objects between delegation and proxying?


Rob J Meijer

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