Validation semantics of time-stamping

["Nick Pope" <pope@secstan.com>]

Following on from the issue that I raised at the DSS conference call ....

I understand that some implementations of the XAdES / TS 101 733
time-stamping attributes / properties are applying the time-stamp after
validation and using this to imply that the signature was valid at the time
given in the time-stamp.

However, I do not believe that there is any standard way to know whether
whether a certain time-stamp is applied only if the signature is known to be
valid at that time.

So I have a question:
 - Is there something that can be added to the XAdES profile or some part of
DSS to enable a party relying on an old signature to be know if the
time-stamp was applied immediately subsequent to successful validation?

Nick