Comment by ekr____

> > The TL;DR is that by the time DANE was created the WebPKI already existed and was universal and so adding DANE didn't buy you anything because you still were going to have to have a WebPKI certificate more or less in perpetuity. > > Yet somehow they managed to wrangle hundreds of CAs to use the CT logs and to change the mandated set of algorithms.

I'm not sure I see the connection here. What I'm saying is that the benefit for sites to adopt DANE is very low because as long as there are a lot of non-DANE-using clients out there they still need to have a WebPKI cert. This has nothing to do with CT and not much to do with the SHA-1 transition.

Re: your broader point about static sites, I don't think you're correct about the security requirements. Suppose for the sake of argument that your signing key is compromised: sure you can change the DS records but the attacker already has a valid DNSSEC record and that's sufficient to impersonate you for the lifetime of the record (recall that the Internet Threat Model is that the attacker controls the network so they can just send whatever DNS responses they want). What prevents this is that the records expire, so the duration of compromise is the duration of those records, just like with the WebPKI without revocation [0]. The same thing is true for the TLSA records signed by your ZSK.

In the DNSSEC/DANE paradigm, then, there are two signatures that have to happen regularly:

- The signature of the parent over the DS records, attesting to your ZSK. - The signature of your ZSK over the TLSA records.

In the WebPKI paradigm, the server has to regularly contact the CA to get a new certificate. [1]

I agree with you that one advantage of DNSSEC is that that signing can all be done offline and then the data pushed up to the DNS servers, but it's still the case that something has to happen regularly. You've just pushed that off the TLS server and into the DNS infrastructure.

More generally, I'm not sure what you mean by a "purely static server". TLS servers are inherently non-static because they need to do the TLS handshake and I think the available evidence is the ACME exchange isn't that big a deal.

[0] As an aside, all the major browsers now have some compressed online revocation system, but that's not necessarily a generalizable solution.

[1] When we first were designing LE and ACME, I advocated for the CA to proactively issue new certificates over the old key, but things didn't end up that way, and of course you'd still need to download it.