I think the main alternatives people suggest are

- something involving a distributed ledger, where revocation isn't even an option, so that clearly doesn't make it better than the current system if we're talking about revocation being a mess (we could just amend the current system to get rid of revocation and throw out a whole bunch of technical complexity if we wanted)

- something involving DNS, which also involves trusting a bunch of companies nobody's heard of (sometimes the same companies, in fact?) who are hardly obviously better at operating cryptographic infrastructure than the existing CAs

- a TOFU approach like SSH, which hasn't been demonstrated to scale well beyond the dozen or so machines in your known_hosts file (most large companies are using something other than TOFU even for internal SSH)

I don't think PKI is an objectively good system, it's just difficult to picture a better one. The main flaws with PKI in practice aren't really about the companies nobody's heard of or a web browser being run by an adtech company - the main flaws are that people want a lot of things out of the system, some of which are contradictory, and running cryptography at this level of scale is genuinely hard. The alternatives don't really address those problems.

Right now, how many different companies could issue a microsoft.com cert if compromised or sketchy? Hundreds?

Right now CAs delegate trust to bunches of questionable sites as seen here with poor oversight or security based on business interest. On a DNS-based system, the entities involved are limited to those who actually manage your DNS.

It also removes the agency of browsers to decide who does and doesn't get to play, which is the current system.

Given that most of the problems with the CA system historically have not been active attacks but incompetence, I don't think we win much from moving to a system where we can, in fact, kick TURKTRUST out of the pool to one where the question is whether .tr remains part of the internet or not. If Verisign screws up with .com in any way short of revealing a letter from the FBI saying "Please help us MITM Windows Update," there will be immense pressure to allow Verisign to continue being the .com registry and continue holding the .com signing keys.

For similar reasons, I'm not convinced that moving from "Hundreds of unqualified companies could issue a bad cert, but hopefully they won't" to "One unqualified company could issue a bad cert, but hopefully it won't" is a meaningful benefit. It doesn't reduce the theoretical bounds on the attacks, and again in practice, these hundreds of companies haven't been misissuing. (The present story is about mis-delegating the power to issue revocation/non-revocation responses, which is certainly a problem, but only relevant in practice if there are actual end-entity certs that are misissued in the first place.) So while it certainly feels better to have fewer entities that can sign - and to be clear, I am all for distrusting many if not most of them - I don't think it addresses either the fundamental theoretical problems nor the actual real-world attacks.

The Verisign CA function was sold to Symantec. That name might ring a bell too, because with these CAs set to be distrusted as a result of Symantec's mismanagement the whole business was again sold to DigiCert in 2017.

I think the perverse part of your reasoning is that you think .com is trustworthy now. It's one of the worst run registries. Its popularity with businesses probably tells you more about how scammy most businesses are than whether .com is trustworthy, and not very much about either.

It's a mistake to separate out the certificate signing authority for different attention if it would be (as in DNSSEC) hierarchically constrained. Verisign can already screw up badly enough to cause Microsoft to lose control of microsoft.com or let somebody else have it. They've apparently decided they're comfortable with their capacity to mitigate that risk. Fine.

That might have worked decently in the early internet but it does seem seriously flawed with the current stakes.

That being said, what's the alternative? TOFU? Web of Trust? Those have massive security implications as well. They have the advantage of putting the user back in control but given that the vast majority of the people using the web today doesn't have a deep understanding of the underlying technology and security model I don't see how this wouldn't end up in a massive catastrophe.

It's a tough problem to solve.

I'd prefer a system backed by DNS, and based on verifying the ownership of domains and the authorized DNS provider for that domain. Presumably, in my example, the only domains Google would be authorized to secure would be domains provided via Google's DNS and domain products.

Um no. Google's four production roots (GTS Root R1 through R4) are essentially dormant. You could (but probably shouldn't) manually distrust these roots with no impact.

Understanding where web security is right now is about understanding who is making the decisions (regardless of any claims about committees and processes), and what motivations they have to make the decisions they do.

Formulating a working alternative is far from trivial.

Never could get the professor to double back around to th He mote problematic stuff.