Re: [Rats] EAT Review Comments

[Henk Birkholz <[e-mail]>]

On 13.12.21 21:31, Laurence Lundblade wrote:
> On Dec 13, 2021, at 4:55 AM, Hannes Tschofenig 
> <[e-mail] <mailto:[e-mail]>> wrote:
>>
>> Hi Jeremy,
>> Thanks for this additional information. That’s very helpful.
>> To me it appears tricky to have the device provide this information. 
>> The problem I can see is that you cannot really rely on it. A 
>> compromised device would lie about its certificate level. Hence, 
>> whoever verifies this information has to keep to a copy around to 
>> check the received data against. This consequently makes the 
>> device-provided DLOA information of limited value.

This characterization sounds more like the use of endorsements to me 
than the use of evidence.

> 
> The EAT claim is just for a pointer (a URL) to the certification info.
> 
> Also, DLOA is more intended for use in Attestation Results so it comes 
> from the Verifier.

And while an Attester can "cache" its own endorsements, typically they 
can also be conveyed to a Verifier from an Endorser, correspondingly

> 
> 
> I actually think certification info is pretty important in 
> characterizing security of something.

+1

> Just as important as the number of 
> bits in an algorithm or the amount of side-channel defenses and such. 
> Certification is where that all gets cross-checked into a coherent set 
> of defenses and where effort is put into finding wholes and gaps. We 
> don’t just say “use big I-beams” when building a sky scraper or bridge. 
> We have a building department and inspector that makes sure they are 
> used right.
> 
> LL
> 
> 
>