On 30 Jun 2005, at 4:16 AM, Ian Grigg wrote:
A little background. This was added by the old
PGP Inc company for commercial users so as to
escrow email. If a key had this subpacket, you
would encrypt to that additional key as well.
Not precisely true. It's a way to have data access to any encrypted
data.
The notion was that it should go
in the standard, but that was politically charged
at the time - indeed Loius Freeh stood up in
front of Congress and used this very feature as
proof that it was possible to force all crypto
programs to escrow messages for the FBI...
No. That's completely false. I have no idea where you heard that, but
that's not at all true.
This is so false that the opposite is true. The FBI hated it because it
was a completely voluntary system with easy workarounds. The FBI hated
it, which is one of the amusing ironies about the thing.
The compromise that was reached was that it
not be documented in the standard. I don't
know if GPG implements it, or even if it the PGP
line still includes it. I think architecturally speaking,
such a feature is better off in the proxy products,
and layered over the top at the admin level
rather than put in the tech. I think it is relatively
safe to ignore it.
It's part of PGP. It's also patented. US patent 6,314,190.
Jon