The problem was that approximately zero users cared, and sites had no incentive to support a login method that didn't have a good solution for account recovery in the inevitable cases of users losing their access.

We've also had TLS client certs with straight up private keys. We have SSH keys too. We have U2F/Webauthn. Using private keys for auth is the easy part. Key management (i.e. people being careless and losing/leaking keys) is the hard unsolved part.

Also, you don't need a blockchain system to have a private key. It's literally just a random number. Blockchains only happen to use them as one of their components. It's like cars have radios, and car wonks saying "cars are about having your own music player. You should put a car in your bedroom to listen to music".

How is this different than the single-signon systems which people have been using for decades? In particular, why should we expect this to be more successful than, say, Mozilla's Persona was?

It would be especially useful if the marketing materials covered the requirements for a serious system like recovering from a compromised or lost key, or how it would avoid the privacy impacts of the same key being used in many places including for purchases? It would be especially important to think about how this would work for normal people — it's not decentralization if you're simply saying that instead of everyone using Google/Facebook/Apple for SSO you're switching to e.g. MetaMask, so a key question would be how reasonable and safe it is for a normal person to operate independently.

'normal persons' will have to change habits. In the physical world, you can lose a coin , irreversibly. Same goes for the virtual. There are no ready made solutions. Lets not assume people are stupid and inflexible, they can adapt to new realities provided the benefits outweigh the drawbacks

How do you think that works? Google can refuse to do business with you but that doesn't mean you can't use a different email provider.

Similarly, if your particular identifier is on some kind of list, changing from an email address to another public identifier doesn't force anyone to allow you access they weren't otherwise planning to give you. If your email address ends up on a list of known spammers, etc. there's no reason why a blockchain address won't go the same way (and if the answer is “I'll keep making new ones”, ask how that's gone for email spam).

> 'normal persons' will have to change habits. In the physical world, you can lose a coin , irreversibly. Same goes for the virtual. There are no ready made solutions. Lets not assume people are stupid and inflexible, they can adapt to new realities provided the benefits outweigh the drawbacks

I'm not assuming they're stupid and inflexible, I'm assuming they're not going to give you money to use a new system which doesn't give them something in return. For example, your conflation of losing a coin with losing control of a wallet is leaving out a lot: if I lose a quarter on the street, I'm out a tiny amount of money but I don't also permanently lose my life savings, mortgage, and ability to login to web sites as in your proposed alternative.

Once you start thinking seriously about real-world usage, you see why even most cryptocurrency proponents pay companies to deal with those issues for them and those banks in all but name are going to be what most people end up using for compliance reasons.

Wallets can indeed be very large "coins". People are going to come up with creative solutions for this, eg. you can split each bitcoins in a different wallet, share the keys with trusted people etc. Cryptocoins are not yet widely used, but there is nothing stopping people from coming up with new ingenious ways to store their hard money safely as they have done in real life. It 's a change of mindset, that it is possible to lose digital assets permanently. I think many people can come to terms with that in the end

You have created a problem where none existed previously, and now speculate about creative solutions to that problem. What isn't answered here is why I should opt-in in the first place.

> It's a change of mindset, that it is possible to lose digital assets permanently. I think many people can come to terms with that in the end

The underlying issue here, I think, is that you perceive all of the systems you're up-ending and re-writing as fundamentally technical in nature. But that's wrong: banking and assets and governance and contracts and everything crypto stakes out as it's domain, they're all fundamentally social problems. You can't write an algorithm to run a country. It's just the wrong model.

So, no, people aren't going to come to terms with the notion that if your ledger slips out of your pocket and into the sewer that your entire identity or all of your wealth or whatever is irrevocably lost. That's just not gonna fly.

Think about this more: we're not talking about a blockchain where the failure is permanent and irreversible. If you forget your Gmail password or someone phishes you, you can go through Google's reset process and regain control. It's still a mess but it's repairable. Similarly, if you don't like Google for whatever reason, email is a distributed system which means you can run your own server or switch providers easily. Similarly, most sites have the concept of linking multiple email addresses or other means to perform a password reset. Nothing about this problem requires turning your internet experience into a series of microtransactions (often not so micro).

> Cryptocoins are not yet widely used, but there is nothing stopping people from coming up with new ingenious ways to store their hard money safely as they have done in real life.

Yes, and they've largely picked the traditional banking system. Most cryptocurrency users use exchanges because those are hard problems which require 24x7 security and operations, and the vast majority of people choose to outsource it.

This is why I suggested studying the long history of this because while the internet has always been decentralized many things people use have increasingly centralized _by user preference_. OpenID had an unfriendly design but it's far from the only thing people have tried, Persona being an obvious example, and in general the public hasn't cared about this enough to even switch to a free service much less a microtransaction-based one.

> It 's a change of mindset, that it is possible to lose digital assets permanently. I think many people can come to terms with that in the end

People have been getting familiar with that for half a century. The difference is that the proposed systems are designed to be fragile rather than robust, cost more to use, and the proposal is to link more of your entire life into those systems without a recovery path. If there isn't a really clear, compelling benefit this is not going to be a successful sales pitch.

Similarly, unless the plan is to tell people that one mistake or hardware failure means they irrecoverably lose their identity, the same process which allows replacing an old key with a new one can be used to replace you.

Finally, there appears to be either no benefit or a big privacy impact mapping keys to profiles on sites. If I go to a website and see “J. Random User” I have to trust that the owner of that site verified their identity against the expected source; if I see something like a signature against a particular key, there's a privacy issue from making it so easy to link you across sites and other activity (yes, people can use ), and if you don't trust the site operator you still have the problem of them showing a different ID when they're doing something dodgy.

I thought, this is one of the main points we want to avoid here, so why are you phrasing it as something so unimportant?

The larger point here is that there's no benefit to the user if the experience is replacing “Login with Google” with “Login with <large exchange>”, which is what it would be for the vast majority of users. If it's saying “Login with your private key”, it would be important to think about why OpenID/Persona didn't catch on or the already-supported x509 key support which has been available for decades.

Why did SIM chips take off? Why did credit cards with smart chips take off? These both embed private keys. Even desktop computers are now embedding private keys in their motherboards.

Clearly, something is missing from your analysis.

- for one-off payments it doesn't matter anyway, you just start using the new card and that's it

- and for recurring payments all businesses already need to allow for updating your credit card details because credit cards regularly expire anyway, so having to possibly manually update all your recurring payments might be a bit tedious and annoying, but it's certainly no impossible, out-of-the-ordinary task

And yet you are unable to say what or offer relevant examples. Do you login in to websites using the key on your phone's SIM or your credit card? Both of those are amusing because they're bot not only irrelevant to the scenario in question but also something people use because that's what they were given, not something they sought out.

> what part of that says “here's a benefit to you which is worth paying $$$ for!” to a normal person?

You get to keep your contacts even if you get booted off the platform (or your contacts do).

And it doesn't cost anything.

* Cancel your account for suspected fraud

* Fall for a password recovery or other attack on your credentials

* Cancel the entire service

* Introduce fees for the service

* Disconnect the identity service from the site where you authenticate

* A blockchain could increase the fees for service. Wait, that happens on a daily basis and you have no control over it.

* A blockchain user could fall for an attack. Unlike the Google scenario, there's no way to regain control of your account – time to setup a new one and convince everyone you work with to update.

* The site you're actually trying to use could switch to a different blockchain (which is more likely than only offering login with Google or that being canceled).

* The site you're using could check a list of addresses and ban yours because it's suspected to be associated with fraud

This is why I suggested taking off your salesguy hat and thinking about what this is like for normal people. Switching to a system which has mandatory upfront inconvenience and expense needs to have a big win to be worth it for people. If it's all “you'll find something to do with it later” you'll get adoption like GPG did.

In this case, I think the key thing to consider is why people use Gmail. It's not like you can't run your own email server, but most people don't want to be responsible for something that important.

A blockchain can be used to tie additional information to the public key.

> The site you're actually trying to use could switch to a different blockchain (which is more likely than only offering login with Google or that being canceled).

I hope they don't use any blockchain at all.

> Unlike the Google scenario, there's no way to regain control of your account

Recovery mechanisms for private key based identities have been designed and implemented.

That is not how blockchain works. Once someone has your private key they can make any transactions that they want, you cannot undo those changes once they are on the blockchain.

So, at best case we have some proof that our key is created/controlled by “me” via a trusted channel but not a centralized authority. Do I upload a video of me showing my public key to the world and upload to some hosting site? Could a deep fake me do that too? Then of course the gpg web of trust model comes to mind, if we attend key signing parties and sign each other’s keys we can verify through associative trust vs centralized trust.

Or is really the point to not have a real world to key identity linkage at all, for “privacy reasons,” and we just all do our business online with full anonymity?