It's a nanny-ish third-party in the middle. That increases convenience, but also greatly increases your threat surface.

Is it nanny-ish just because it makes it simpler for end users? Fairly certain most users are not interested in managing their own key sharing infrastructure.

It's built on the same technology as FIDO keys, so if you want to take control of it yourself, just use a hardware key.

Exactly.

Now, why are they doing it for free? Why take on a huge responsibility for no money, what do they get out of it?

If people use this instead of passwords, they get less compromised accounts on their services that they have to deal with.

Less customer support for dealing with hacked accounts. Same reason places support and even push 2FA, otherwise what is their incentive to support 2FA?

Fortnite even has a free dance that you can only get by enabling 2FA.

Be precise: what threat is added here that is added by a third party holding encrypted keys?

Like this isn't particularly different from me backing up my (encrypted) disk which contains my (further encrypted) keys to the cloud somewhere.

In the second instance, you are controlling the where and how of your keys being backed up. If you are smart you will have backed up your keys to multiple locations, for disaster recovery. One of the fundamentals of privacy is having control of your data, which the first option does not provide.

Why not?

What is concerning about giving encrypted keys to someone? If I give my encrypted key to you, right now, I retain control of my data. One of the fundamentals of encryption is that you can freely share the ciphertext without giving up control of your data.

I don't know, and you don't either, because I'm willing to bet that "Google" is smarter than both of us.

That's kind of the point. We have to trust that Google won't mess things up and we have essentially no recourse if they do.

I'm unclear on what you think they could do. Is your idea here that Google is so smart that they can break end to end encryption? If so, we've got bigger problems.

It isn't fair to presume that everyone shares your lack of knowlege on a subject, and it's simply incorrect to presume that because you don't understand something that it cannot be safe or reliable.

What they say today about end-to-end encryption seems like it should work fine from a technical point of view. It is entirely possible the Google is very good about this, and when implemented, it might work perfectly as stated today.

But I'm not talking about incorrect or correct and I don't care about fairness in presuming whoever's intelligence either, because the thing I'm talking about is more important, which is risk.

Large companies taking on big tasks that you don't pay them for is undeniably risky for many reasons. One, they screw it up today. Two, they don't screw it up today but they change it tomorrow. We know this because many of these companies have done things like this before.

But again, what is the unique risk here? Google shutters and your phone bricks simultaneously, and you're left unable to log in?

Like this is lower risk than a local password manager or a yubikey or... Because it's both local and cloud backup. Be precise, what is the risk?

No, those are the same thing. The "not your keys" thing in crypto is exactly the reason they tell you NOT to store your crypto with e.g. Coinbase/Binance. Just use them as on/off ramps, but have your own wallet.

And BigTech's cloud (who will have no problem sharing it with the authorities). And when all your keys are on the device, it also becomes a lot easier for the government to access all your internet accounts by getting access to the device.

They're end-to-end encrypted. Did you read the article?

This is the same threat model as password managers, which are generally approved of on HN.

You can backup your password manager.

You don't have to depend on the cloud for your password manager.

Who cares if it is "end-to-end encrypted" if the device with all your keys / credentials can be easily used to access all your online accounts? (And no online service forces me to use a password manager).

Yeah, I think HN is mostly wrong about those as well. :)