Series of minor questions about OpenPGP 1

[Peter Thomas]

On Mon, Jan 26, 2009 at 5:40 PM, David Shaw <dshaw at jabberwocky.com> wrote:
>> Ah, thanks. So I'd should be 254 for better security of the private key, right?
> Yes.  See http://eprint.iacr.org/2002/076.pdf for the attack that
> prompted this extra layer of protection.
Ah,.. interesting,.. thanks for that pointer.

>> Uhm, I just wanted to follow the recommendation of the RFC ;-)
> The RFC says "If interoperability is not an issue, the new packet
> format is RECOMMENDED."  Given that interoperability *is* an issue
> (GPG works with PGP 2.x), we don't use the new packet format except
> when necessary.
Ah,.. ok so to support older applications. Good decision.
Uhm what happens if one of these older implementations sees a packet
type above 15? Do they give a warning? Or is there something similar
to the critical bit?

>> But there is probably no function in gnupg to do this conversion, is
>> it?
> No, but you could patch it if you liked.  Take a look at the
> write_header() and write_new_header() functions in build-packet.c
Thanks for that info,.. but you're right and it's probably better to
stay with the compatible-mode.