Re: SOI QUESTIONS: 2.3 Perfect forward secrecy (PFS)

[Henry Spencer <henry@spsystems.net>]

On Thu, 20 Jun 2002, Tylor Allison wrote:
> ...Without
> a clear and concise mandate from this WG on the minimum requirements for
> PK/PKI, there will be interoperability problems...

Yes, and this is a problem... why, exactly?  This just means that such a
solution must include such a clear and concise specification of how to
proceed.  That doesn't seem contrary to the laws of physics; surely it can
be done. 

> ...The same really can't be said for pre-shared keys...
> they are simple, straight-forward, and almost guaranteed to interoperate
> between any two vendors.  Why throw it away?

Because there is a price, one that may not be worth paying.

I would be happier about adding/retaining a second authentication scheme
if it paid for itself in some other way too, e.g. the suggestion that a
well-designed shared-secret authentication scheme could also handle most
of the legacy-authentication problem.

                                                          Henry Spencer
                                                       henry@spsystems.net