-----Original Message-----
From: owner-ietf-smime(_at_)mail(_dot_)imc(_dot_)org
[mailto:owner-ietf-smime(_at_)mail(_dot_)imc(_dot_)org] On Behalf Of Housley,
Russ
Sent: Monday, October 21, 2002 4:43 AM
To: bernd(_dot_)matthes(_at_)gemplus(_dot_)com
Cc: ietf-smime(_at_)imc(_dot_)org
Subject: RE: Ordering of encryption and signing of a S/MIME message
An attacker can strip the SignedData encapsulation, making
the recipient
think that the originator sent an encrypted-only message.
However, this
construct is safe if the recipient will disregard any
unsigned messages.
Another argument in the early days was that "encrypt and then sign"
would allow an opponent to collect the signature information from the
message.
From a client perspective, it might be interesting to see how well they
behave when presented with a signature around encryption. The "What
Would Outlook Do" argument.
Blake