Re: [openpgp] Can the OpenPGP vs. S/MIME situation be fixed?

Peter Gutmann <> Sat, 02 July 2016 15:09 UTC

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From: Peter Gutmann <>
To: Phillip Hallam-Baker <>, Derek Atkins <>
Thread-Topic: [openpgp] Can the OpenPGP vs. S/MIME situation be fixed?
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Date: Sat, 02 Jul 2016 15:08:55 +0000
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Cc: IETF OpenPGP <>, Hanno Böck <>
Subject: Re: [openpgp] Can the OpenPGP vs. S/MIME situation be fixed?
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Phillip Hallam-Baker <> writes:

>I have wanted this for a long time. there are actually three separate
>problems to be solved.
>1) How to make S/MIME work with OpenPGP credentials
>2) How to make OpenPGP work with S/MIME credentials
>3) How to merge the two specifications into one.

The first two are pretty easy, I've been doing that for years.  For S/MIME,
use the subjectKeyIdentifier form of the key ID.  For PGP, use an
issuerAndSerialNumber in a type-and-value subpacket.

The third is impossible.  While at an abstract level PGP and S/MIME do the
same thing, the bit-bagging formats used to encode the abstraction are
completely incompatible.  You can't make them compatible without either moving
S/MIME to the PGP format or PGP to the S/MIME format.  I can't see either of
those happening...