In earlier versions of Acrobat and Reader, certain revoked Digital Signatures that displayed as invalid, now display as valid signatures in Acrobat and Reader 9.1. We’ve released a new TechNote that describes this change and how you can make a few changes to return to the original behavior of Acrobat 9.0 if you feel the need.
Why the change?
While the signatures may have been deemed invalid in the past by Acrobat, the signature validation time change shows that the signatures actually were valid at the time of signing… but may not be valid today. This is an important distinction which we felt was critical to bring out in 9.1. We feel that signing time is a more accurate portrayal of the status of the signature, rather than current time.
Read the complete TechNote, Certain revoked Digital Signatures which in Acrobat and Reader versions prior to 9.1 displayed as invalid, now display as valid signatures in Acrobat and Reader 9.1. That’s the title – seriously.