Verifying signatures fordocuments signed looong time back..

["Jayant Sane" <jayant@xxxxxxxxxxxxxxxx>]

Hi,

Forgive me if this issues/question has been discussed in past or is an
improper post for this list. I did not find anything on this topic in the
archive (unless I overlooked something).

How does one "correctly" verify a signature such that the signing
certificate has expired. Basically during the time of verification (anytime
after the signing operation), how does correctly establish that the signing
certificate in consideration was valid then ?

Is it at all feasible (it better be)? If yes, does it call for maintaining
some extra information at the time of signing?

-Jayant