Re: [Trans] Martin Duke's No Objection on draft-ietf-trans-rfc6962-bis-39: (with COMMENT)

[Ryan Sleevi <[e-mail]>]

On Thu, Jul 29, 2021 at 4:30 PM Salz, Rich <rsalz=
[e-mail]> wrote:

> The signature algorithm is unlikely to change until we have to deal with
> post-quantum signatures, and that is years away. As for the key being
> rotated, this is not a short-term WebPKI TLS key, but rather a long-term
> data signing key. So far none of the logs being used (I hesitate to say “in
> production”) have had to do either.
>

I'm not sure this is correct, Rich? Logs regularly rotate IDs; presently
annually, but it's reasonable to anticipate more frequently as the
size/performance tradeoffs, precisely as the way of pruning the storage.

For example, it's a policy requirement for present CT enforcing agents that
logs be temporally sharded, such that a log does not accept certificates
that expire after a defined point, so that the log can be retired after
that point.

Effectively, the log ID space is as wide as the private key space. The
switch from (key hash) to OID largely removes the dependency on both the
hash algorithm and can reduce the size of the ID. The existence of the
registry is simply to allow for smaller encoding than using a Private
Enterprise Number, as stated in the draft. That is, the registry is simply
a form of compression :)