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RE: Please save the pre-shared key mode

On Thu, 6 Dec 2001, Wang, Cliff wrote:

> While I agree with you that self-signed cert plus out-of-band trust models
> may be an alternative way to deliver IKE credentials, I would like to see it
> in a more standardized format and a wider acceptance by the industry.

Good idea. So let's expend out energy on that, instead of adding pre-shared
symmetric keys to protocols.

> On the
> other hand, PSK based IKE and PKI based IKE has been the main way people
> deploying VPN. Under that context, PSK is simpler to run than PKI.   
> 
I think that's the myth Dan was talking about.

jan



> 
> -----Original Message-----
> From: Dan McDonald [mailto:danmcd@east.sun.com] 
> Sent: Thursday, December 06, 2001 1:28 PM
> To: Wang, Cliff
> Cc: ipsec@lists.tislabs.com
> Subject: Re: Please save the pre-shared key mode
> 
> 
> > 1) Simplicity
> > Pre-shared key mode is simpler to support by eliminating the 
> > requirement of supporting complex PKI.
> 
> It's a myth that public-key implies you MUST have a PKI.
> 
> Self-signed certs combined with explicit out-of-band trust models is just a
> non-cumbersome as pre-shared keys, IMHO, and they also offer
> IP-address-portability.  (Henry Spencer, correct me if I'm wrong, but
> FreeSWAN has a self-signed cert model that works, right?)
> 
> If we keep pre-shared, let's have a scalable way of identifying them.  In a
> multi-homed world (esp. IPv6), pre-shared keys indexed by address pairs is
> as much hassle as PKI registration (it's just less snake-oil than most PKIs
> ;).
> 
> For testing, I run server machines with self-signed certs.  For small
> (10-100) numbers of clients, it works out _quite_ nicely, and w/o any of the
> PKI cruft.  Peer-to-peer explosions is about the only case where PKI is
> really needed, and pre-shared won't help you any there either.  It's just a
> matter of running certificate-generation, e-mail, and verifying hashes
> out-of-band.
> 
> I'm not totally against nuking pre-shared.  It's not, however, the panacea
> of simplicity many think it is, and simplicity arguments don't hold water.
> 
> Dan
> 

 --
Jan Vilhuber                                            vilhuber@cisco.com
Cisco Systems, San Jose                                     (408) 527-0847
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