[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Emphasizing a point by Donald Eastlake re key recovery
> Date: Wed, 24 Sep 1997 10:15:45 -0400
> To: Ross Anderson <[email protected]>
> From: Carl Ellison <[email protected]>
> Subject: Re: Emphasizing a point by Donald Eastlake re key recovery
> Cc: [email protected], Ron Rivest <[email protected]>,
> [email protected]
> Reply-to: Carl Ellison <[email protected]>
> -----BEGIN PGP SIGNED MESSAGE-----
>
> At 09:34 AM 9/23/97 +0100, Ross Anderson wrote:
> >There is also the point that the vast majority of encryption keys are
> >actually used for authentication rather than confidentiality. The keys
> >that encrypt your bank card PIN en route from the ATM to the bank, the
> >keys in your satellite TV decoder, the keys in your gas meter and your
> >postal meter - in fact the majority of all DES keys in use - are about
> >authentication. In theory most of them could be replaced by digital
> >signature mechanisms but given the size of the installed base, it
> >won't happen anytime soon.
>
> For what it's worth, I once got an opinion from NSA's export control office
> that I could use any kind of crypto I wanted (e.g., even triple-DES) if all
> I'm doing is protecting a channel carrying a password (like the PIN),
> because that's an authentication function and therefore to be encouraged. I
> didn't get this in writing, however, so I'd have to go for it again.
>
> - Carl
Well, I dunno. About 18 months ago, I was involved with the
negotiations over the exportability of an SSL equipped web
server I had helped develop. The export model used 40 bit RC4
and 512 bit keys. The initial version used 3DES to encrypt
stored private keys, and this was turned down. I modified it to
use single DES, and it passed.
Note that this was for secret key storage only.
Peter Trei
[email protected]