Re: [Rats] use case document updates on Roots of Trust

[Michael Richardson <[e-mail]>]

Salz, Rich <[e-mail]> wrote:
    > I do not see a meaningful difference between "trust anchor" and "trust
    > root" and "root(s) of trust."  All of them:

    > - Are pieces of data (certificate or key is not meaningful)
    > - Used to verify something such as a certificate or signature
    > - Are trusted by the application, based on actions that are "out of
    > band" of the application itself

That's because the term "root of trust" as used by attestation people are
very confusing.  And it's precisely your confusion that I would like to avoid.

** A root of trust is a piece of code that measures itself, because nothing
** before it can do that. (It might be the first piece of code to run).

While it is true that a trust anchor (in the form of a self-signed
certificate) comes with a similar kind of circular/implicit trust, the
measurement made by the root of trust code can actually be attested to by a
third party, and this is typically done.

The trust anchor used by a relying party to verify this attestation may also
come with implicit trust, the verification of the measurement made by the
root of trust does not.

I think that terms RoT Storage/etc. are even more confusing.

--
Michael Richardson <[e-mail]>, Sandelman Software Works
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