[HELP NEEDED] GnuPG-1.4 IDEA migration to GnuPG-2.0

[David Shaw]

On Sun, Jan 28, 2007 at 07:33:15PM +0000, Benjamin Donnachie wrote:
> Alon Bar-Lev wrote:
> >> Do they /absolutely/ need to use GPG v2?  If not, it's probably going to
> >> be easier if they go back to using v1.4.x...
> > This is the easy way out :)
> 
> It's the one the gnupg team recommend!
> 
> > gpg2 should be backward compatible... I would like to make it work
> > too... :)
> 
> I understand that IDEA isn't OpenPGP compatible and, besides, the 1.4.x
> branch will continue to be maintained and developed.

It's not true that IDEA isn't OpenPGP compatible.  IDEA is cipher #1
in OpenPGP, and the new RFC does not change that.  It is absolutely
part of (though an optional part of) OpenPGP.

The problem with IDEA is that it is patented, and will be patented for
at least 3 more years (the exact end date depends on which country
you're in).  Without going into endless detail, patented algorithms
and the GPL license are not really compatible with each other.

Even so, ask if you really need IDEA or not.  Unless you have a
serious need for PGP 2.x compatibility, IDEA doesn't buy you much.

David