One Party Consent Model

jfcm wrote:

[I separated this response from the others and gave it a new subject, 
since I believe it's important]
> > Hm, you bring up a good point. For example, your asking who are the 
> > endpoints when I send an email to a mailing list, right? I've one 
> > source endpoint, but multiple destination endpoints. So it's not 
> > sufficient if only one of the endpoints authorizes a service.
> > Now, in case of this example, sending to the mailing list results 
> > basically in multiple transmissions to individuals, in which case 
> > we're back to a scenario with two endpoints.
>
> No. For several reasons.
>
> 1. the mailing list the information is sent to is part of the 
> information. That information cannot be modified without the agreement 
> of the whole mailing list. If I send a mail to this list saying that you 
> do not understand this point and I make an OPES to remove you from the list
>     - I agree so it is OK by your criteria
>     - you will not respond, so everyone will believe you do not object
>     - I send another mail agreeing but I make an OPES changing the from 
> jfc in from markus (I can do it since I am one end). Everyone will 
> understand that you have agreed not understanding this point
> ... and you will know nothing of this.
>
> 2. Again I am A, you are B and someone is C. An OPES changes B in C. C 
> will be the receiving end. He has agreed to the change. Is that enough? 
> May be if B gave authority to C, maybe not if B has not.
See your point, but the example you outline above violates the OPES 
tracing requirement, which says that Markus (or B in the generic 
example) must be able to trace the OPES service. I.e. I would be aware 
of the OPES service that removed me.
Now, I'm not yet sure how to achieve this and whether this is the 
full/correct answer...
-Markus