Re: Best practices for signature verifcation

[Simon Josefsson <simon () josefsson org>]

I forget a major aspect the competition is doing worse than PGP: public
key distribution.  While PGP key distribution has been a continous
problematic matter, it may be because the PGP ecosystem attempts to
address this problem and the other sign+verify technologies has given up
on solving it.

Collin Funk <collin.funk1 () gmail com> writes:

> Doesn't Sigstore require a centralized Rekor instance? That was the
> impression I based on a very brief look at it previously.

Yes, but I don't see that as a major problem since the transparency
model uses monitors/witnesses to keep instances honest.  Same situation
with Sigsum really.  Sigstore/Sigsum offers properties none of the other
solutions offer, so it may be a price that we need to pay to get those
properties.  I think this is somewhat different compared to other
centralized services patterns, which is generally a deal-breaker.

Demi Marie Obenour <demiobenour () gmail com> writes:

> I do think that better CMS/PKCS#7 implementations would be worth
> pursuing.  This is because it is hard-coded into a huge number
> of applications that will be extremely difficult to change.
> These include:
>
> - Windows and UEFI Authenticode.
> - macOS and iOS code signing.
> - Legally binding CMS Advanced Electronic Signatures (CAdES).

Why is compatibility with that an argument?  I don't think CMS/PKCS#7
offers anything compelling that PGP doesn't, and the complexity is
horrible (just think ASN1).

> Would it be possible to standardize some form of metadata for SSH signatures?
>
> CMS and OpenPGP support time-stamping countersignatures is critical.
> This is critical for some applications, notably Authenticode and CAdES.
> Should this be supported?

Is that a critical feature for a signature format?  Why not just design
a metadata format for that use-case, and sign the metadata using SSH
signatures?

Feature creep in signature systems seems to be a big problem that
eventually turns them into a copy of PGP or CMS.

/Simon

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