RE: [dss] EPM use cases: some questions and one requeriment.

[Trevor Perrin <trevp@trevp.net>]

At 01:53 PM 6/25/2003 +0200, Gray Steve wrote:

>Dear Colleagues
>
>I have attached a document where I have collated most of your questions
>regarding the EPM use cases and provided answers.
>
>Please let me know if there are further clarifications required and I can
>prepare something for discussion at Monday's telephone conference.

Thanks,

My questions that remain, which we can discuss in email or at the concall:

What is the point of the sender acquiring a "postmark" on his document?  To 
whom is this postmark meaningful, and what does it mean?

According to A11, "The main purpose of the EPM is to provide a 
non-repudiation service that attests Who, What, Why, When a document was 
signed, plus the archival service".  Isn't this provided by a normal, 
time-stamped digital signature?

Why is the archival service necessary?  How is it used?  A use case that 
demonstrated the entirety of the legal challenge/dispute resolution process 
might make things more clear.  Otherwise I'm not sure what attacks these 
measures are meant to defend against, or what requirements they're meant to 
fulfill.


Trevor