[Discuss] Why the dislike of X.509?

[Richard Pieri]

On 8/28/2014 2:49 PM, Bill Ricker wrote:
> Kerberos KDC is limits the attack surface instead of concentrating it,
> and implements session key negotiation without requiring asymmetric
> (PubKey), although public key is available for authentication.  pretty
> slick.

Very flexible, scalable, and designed to operate reliably on actively
hostile networks.

> ( Don't think it would scale to the whole internet though, as we have
> other requirements there. )

It would require reversing how we typically handle authentication.

Imagine a Kerberos realm deployed by Amazon. That's going to be a
massively ginormous database. Not scalable short of throwing massive
quantities of hardware at it.

Turn it around. Instead of me joining Amazon's realm, what if Amazon
joins my personal realm? My KDC is the origin of the service principal
that Amazon uses when we (that is, my browser and Amazon's web servers)
communicate with each other. My KDC is the trusted third party for our
mutual authentication.

It's not simple but it is very, very scalable. It's also much more
secure as an entire system as the compromise of my KDC only affects me.
That compromise cannot be used to exploit other private realms.

-- 
Rich P.