"David E. Smith" writes:
The question is: how do the current software packages handle representatives and proxies for a given is-a-person? Using PGP as an example, I can't sign a message with Helen's key.
Nor should you be able to, actually. When you sign a document on behalf of another and have "Power of Attorney" in the paper world, you sign your own name and indicate that you are signing on behalf of another, as in "David Smith for Helen Smith". The right way to do this in the digital world, IMHO, is to have a standard for "Power of Attorney" documents, and for the entity receiving something signed in your key that should be signed in another person's key to also see the digitally signed power of attorney document. Then the entity can check the signature on the power of attorney was in Helen's key, and that the signed key in that document was the key that signed the document signed by the "attorney".
I'm sure that this has already popped up, so I'll just ask for pointers.
Actually, I haven't seen it mentioned before -- its only a subset of other problems, though, like transient keys signed by longer term keys. There should be some standardization in formats to handle this. Perry