[EGreg]

It doesn’t solve this problem at all. The site says:

How do you know that Google's public key is actually Google's public key? When you make that first request to Google, an intermediate network may have intercepted your request and returned a fake public key for Google. CAs attempt to solve this problem. CAs are trusted third parties that verify the authenticity of public keys for websites.

How does proof of work ensure that google.com really goes to Google and not someone who paid $2,000 to mine something?

[troquerre]

A miner wouldn’t be able to do that. Only the private key owner of Google could do that. At most a miner could do a double spend attack (would cost a lot more than $2000), but that wouldn’t change the DNS record for Google.

[EGreg]

The question is how do you know that the owner of the private key is the “owner of GOOGLE”. That’s what CA’s solve. Blockchain doesn’t solve this problem.