Re: [dane] Behavior in the face of no answer?

[Eric Rescorla <[e-mail]>]

On Fri, May 4, 2012 at 12:02 PM, Martin Rex <[e-mail]> wrote:
> Eric Rescorla wrote:
>>
>> Before we discuss how to proceed, I think it would be useful to get
>> agreement on the security analysis.
>
> Analysis (about what the attacker could do) is correct, but ...
>
>>
>> I claim that for Usages 0 and 1, treating TLSA non-response as if no
>> TLSA records exist means that DANE adds minmal/no security value for
>> those usages. If people disagree with that,
>
> I do not fully agree to the conclusion.
> With the exact same logic, when comparing DV-certs to EV-certs, you
> could say that EV-certs add minimal/no security value.

It's precisely for this reason that EV certs add minimal security value.


> Web Browsers provide visual cues to differentiate DV/EV-certs (since
> very few users look at the certificate details.

There's very little evidence that users treat these indicia differently.
Adding yet another indicator seems to make the cognitive overload
problem even worse.

-Ekr