Re: OpenPGP keys and Suite-B

["David Crick" <dacrick@xxxxxxxxx>]

>  So given that new programs will need to have 3DES anyway to cover the
> transition case, and given that messages sent to a mixture of old and new
> keys that are forced to use the cipher of last resort will end up as 3DES....

This is (mainly) about ECC keys,  and specifically about the
implementations' [ability to enforce] Suite-B compliance.

As old applications won't be able to understand ECC keys *at
all*, we've "almost" got a clean sheet with what we do with
ECC keys.  "Almost," because at present ECC keys inherit
3DES as the default cipher from 4880.

> how is (B) different than the current cipher preference system with
> AES listed before 3DES?

right - which is why my original proposal was for a stronger
suite B flag, which says implementations MUST NOT process
messages that fall outside of the Suite-B restrictions (that aside,
Andrey has written in "OpenPGP technical/documentation terms"
what I was originally trying to get across with my perhaps wrong
terminology of a Strict Suite-B "flag").

(And to directly answer your question, Andrey's B is slightly different,
in that while the preference system *is* ordered, implementations
currently have free rein at how they use the intersection of
recipient preferences; Andrey's B says that AES should be used
in place of 3DES - but as you've (now) pointed out, for non-ECC
keys this may mean some people receiving AES messages when
in fact they can e.g. only process 3DES ones).