Re: [Rats] Quantum-safe attestation

I don’t want the RATS architecture to pick one algorithm or go into detail about algorithms.

I expect the RATS architecture to be fully flexible to use what ever algorithms can do the job. In particular it must not assume PKI. Most other crypto-using IETF standards do not assume PKI. They often work better with PKI, but they allow for other algorithms. RATS needs to be the same.

The particular manifestation I can think of for RATS is that Endorsements must support confidentiality. If endorsements do not support confidentiality an assumption that only PKI-based attestation can be used is made. 

I don’t know of any other manifestations that moving to quantum-safe crypto would have on the architecture, but it seems worth thinking through.

LL

> On Aug 24, 2020, at 2:16 PM, Michael Richardson <mcr+ietf@sandelman.ca> wrote:
> 
> 
> Laurence Lundblade <lgl@island-resort.com> wrote:
>> We probably want RATS architecture to be able to use quantum-safe
>> algorithms. On low cost and low speed devices that might mean HMAC is
>> used since SHA-2 and such seem to be quantum-safe. On higher cost and
>> higher speed devices there may be alternatives that look more like
>> PKI.
> 
> Yes/no.
> 
> Use of a keyed HMAC requires a symmetric key, which will be a hassle to
> provision the verifier, and effectively locks the device to a single (likely
> manufacturer provided) verifier.   It will also raise questions of
> non-repudiation.
> Better *might* be RFC8778 HSS/LMS Hash-Based Signature Algorithms.
> They are bigger, and have a limited number of uses.
> 
> I would say that the architecture does not need to say anything about the
> algorithms.  These are functional requirements, not design requirements.
> 
> There will have to be firmware updates to the Attesting Environment once
> either we have quantum-safe asymmetric algorithms, or when we have a QM
> breach.  That can be done with SUIT signed by RFC8778.
> I don't think that our architecture need worry about that.
> 
> --
> Michael Richardson <mcr+IETF@sandelman.ca>, Sandelman Software Works
> -= IPv6 IoT consulting =-
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