So it doesn't matter on what hardware, if you want bcrypt to take 1 second on modern hardware (for any value of "modern"), you can.

The concept actually makes sense, but it kind of assumes that the strength of the security will be increased at the same rate of which technology progresses, which I don’t think will always be the case. This is especially true when you consider potential “bursts” in computation speed progression.

That being said, I’m not implying that I have a better idea. Running algorithms that take 30 seconds to execute isn’t going to work for logging into your Twitter account either.

Make it 15ms for an attacker and it becomes an hour per account just for the dictionary.

You also can't assume that all accounts are equally valueable. An attacker might very well prioritize some of them.

This doesn't render all of this useless but I think you shouldn't consider even best solutions out there to be anything else than a temporary barrier. It's a good one and you probably will have enough time to change your password after a leak but you really do need to change your password within a week or so.

But I think the parent's point was that this compute time only lets you check one password against one account. All you can do, after this compute time, is state that "'monkey' is/ is not the correct password for @iagooar's account".

Those results can't be used to check other accounts (because they're salted) so this approach doesn't really scale well at all. It might, for a huge adversary (state-scale) allow a single password to be cracked in a reasonable timeframe, iff it's relatively simple password.

An evildoer would use stolen credentials, stolen credit cards, or stolen hardware (botnets).

It's hard to get specific numbers about a trend that just changed. But the double every 18 months is now clearly wrong.

We've got a couple of approximately 27 months doubling, but that is past too. My bet is that we won't get a fixed number ever again.

So maybe that's the way for computers to become much faster, making everything around the CPU go faster. Integrate the RAM and the GPU on the chip. Superfast SSDs. Etc.

107 kHashes/second/machine for bcrypt in default settings (which probably many sites will use).

If they did indeed use a work factor of 5 then this analysis is pretty much meaningless for bcrypt. The default is 10 and I usually use 12 myself.