Re: separation of signed and encrypted messages

["Michael Young" <[e-mail]>]

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>but is there any way to do it, short of rewriting gpg, pgp to include a -d
> > command similar to the -d command of 2.6.3?

It doesn't appear that GnuPG has such a switch now.  But it would
be easy to build.

> one could simply {from a remote area, without anyone needed to 'witness'
> the decryption process}
> separate it into the armored signed file, and release that to the
> 'authorities', and show that it had to have come from
> the specific signed and encrypted e-mail in question.

No.  The message(+signature) contents are symmetrically encrypted.
There is no way to prove that the plaintext generates that specific
ciphertext without giving up the session key.  Demonstrating
a decrypted signature or MDC shouldn't convince anyone that the
full plaintext matches that ciphertext.

If you're willing to show the plaintext, why do you care about
protecting the session key?  Are you reusing it?  This might be an
issue for a PGPdisk, for example, where one symmetric key protects the
entire contents...  you can't reveal+prove selected parts.  It
shouldn't be for ordinary OpenPGP uses.  Are you afraid that
your randomness source has been compromised, such that other
session keys could be deduced?  If so, you have a serious problem.

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