Re: dnssec discussion today at noon

[Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>]

Brad;

> >>  	And what does this have to do with DNSSEC?
> >
> >  The theory explains the reality that public key cryptography
> >  (including DNSSEC) is not used for serious purposes.
> 
> 	Not used for serious purposes?!?

No, not at all.

> Okay, let's have you run a B2B 
> website where billions of dollars can be moved with the click of a 
> single mouse button.  Now, we have to ensure that you really are 
> interacting with the real B2B website and not some clever fake, or 
> worse, some site that performs a man-in-the-middle attack on you 
> while you are conducting a real transaction, so that they can later 
> go in and conduct multiple fake transactions.

Are you saying that the B2B website gladly accept a billion dollar
order from some unkown company just because a CA says the company's
domain name is not faked?

Purely techinically, if secret is shared between the website and the
company, shared key cryptography protect you from a clever fake and a
MITM attack.

But, it is not enough credential to perform serious commercial
transaction. The website should check credit status of its
members.

> 	How about home banking?  Sure, hundreds, thousands, tens of 
> thousands, etc... of dollars may not be a whole lot of money to you, 
> but they may be the entire life savings of a family.  Multiply that 
> by 250 million people in the US alone, and you're talking about some 
> real money.

Protection for home banking is by shared secret.

> >  Such security is not useful for serious purposes, when no one is
> >  really responsible if your transactions are spoofed.
> 
> 	Okay, so we can all sue you for billions and trillions of dollars 
> worth of damages when someone spoofs a DNS response packet which then 
> leads us to be vulnerable to man-in-the-middle attacks.

Huh?

You can't ask root server operators for compasation for billions
and trillions of dollars worth of damages when someone spoofs a DNS
response.

Serious users protect them with shared secret. They don't blank-mindedly
rely on CAs not really offerring any serious compasation.

> 	No, in both cases.  There are a multitude of heinously screwed up 
> servers in this world, and a multitude of heinously screwed up 
> routers, too.

And, there will be multiple screwed up CAs. Or, are there already?

So, have weakly secure Internet and DNS as a infrastructure and don't
rely on intermediate entities of servers, routers or CAs.

							Masataka Ohta