RE: SOI QUESTION: 5.2 Scope of proposals

[Henry Spencer <henry@spsystems.net>]

On Thu, 11 Jul 2002, Jayant Shukla wrote:
> >   We NEED a MUST suite for end-to-end security to work.
> 
> I don't completely agree.
> What you NEED is a centralized management for e2e security to work...

You're saying that it's completely impossible to design a protocol which
will interoperate without centralized management?  Why? 

We have many examples of Internet protocols which interoperate without any
centralized management.  There is no fundamental reason why crypto should
not do likewise... and many reasons why it is highly desirable for it to
do so.

> MUST suite only solves part of the e2e problem.

True.  Other issues need solving too.  They too can be solved.

> Using the centralized
> management, you can always ensure that host policies and suits are in
> sync. 

Certain very important classes of communications problems inherently lack
any centralized management. 

> > We need a backup
> > suite to transition to should the initial suite turn out to be broken.
> 
> If you know specifically what might turn out to be broken, one backup
> will suffice. Otherwise you will need more than one backup.........

Not necessarily.  If the prime is AES+latestSHA, and the backup is
3DES+MD5, where is the common failure point?

                                                          Henry Spencer
                                                       henry@spsystems.net