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Re: SOI: identity protection and DOS
On Wed, Nov 28, 2001 at 01:46:07AM -0500, david chen wrote:
> I try to say that
> if self-signed certs depend on the out-of-band 'secured channel' that
> is used the same as pre-shared key for its key management,
> then why not just use pre-shared key? and save the trouble for
> public/private keys.
>
> Don't see the advantage of using 'self-cert' over 'pre-shared' in this case.
For pre-shared keys, your secure channel *must* be private. For
self-cert, your secure channel to verify the key does not depend on
privacy for security. This is the whole point of PK.
This seems fairly obvious to me. ...or am I missing something?
> --- David
>
>
> ----- Original Message -----
> From: "Steven M. Bellovin" <smb@research.att.com>
> To: "david chen" <ietf_davidchen@hotmail.com>
> Cc: "Paul Hoffman / VPNC" <paul.hoffman@vpnc.org>; <ipsec@lists.tislabs.com>
> Sent: Tuesday, November 27, 2001 7:39 PM
> Subject: Re: SOI: identity protection and DOS
>
>
> > In message <OE20dgLXZ3lV3Rr4Ygc00005184@hotmail.com>, "david chen" writes:
> > >The very reason to certify a public key is that
> > > if the key is not 'public' enough than it is subject to MIM attack.
> > >
> > >Self-signed cert is subject to MIM attack unless...
> > >then why we need public/private key.
> >
> > You misunderstand. I'm suggesting that whatever secure channel could
> > be used to share a symmetric key could be used to share a public key.
> > If you can't trust that channel, you can't use pre-shared secrets,
> > either.
> >
> > --Steve Bellovin, http://www.research.att.com/~smb
> > Full text of "Firewalls" book now at http://www.wilyhacker.com
> >
> >
> >
slainte mhath, RGB
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