I can think of one use for blockchains that can't easily be replicated otherwise (at least not with the same amount of security), it's proving that you knew something at some point in time. Putting something in the blockchain is like taking a picture of it with today's newspaper next to it so to speak, except you can't photoshop it.

If I made a groundbreaking discovery today, putting a sha-256 of it into the blockchain would be a very good proof later on that I actually owned it at this time.

But beyond that I agree with you. My (non-technical) girlfriend is looking into cryptocurrencies lately and she watches tons of youtube videos about it while doing her research (TEDx talks and the like). Easily 90% of the claims of "blockchain is going to revolutionize X" are easily dismissed either because the blockchain can't do what the person claims or there's an other, often simpler solution to this same issue. "Use the blockchain for food traceability", "use the blockchain to validate critical equipment firmware" etc... It sounds good as long as you don't think about it for more than 10 seconds.

The problem is that in order to realize that you need to have a rather deep technical knowledge about how the blockchain works, something 99% of people investing in crypto probably lack.

That still doesn’t require a full blockchain: 90s PGP with multiple signatures is all you need, or going really old school, mailing a copy to yourself using registered mail.

Imagine if a notary, post office, etc. set up a signing service: relational database, basic signatures for user-submitted hashes, etc. Not quite as good but much cheaper to run and much easier to have trusted by a court — I suspect most users would see no additional advantage by adding a blockchain.

The change is in the trust model.

The centralised approach described requires that one trusts the database administrator. For a lot of things (probably the vast majority), this is good enough.

For the rest, there's decentralised distributed immutable ledgers.

Trust is an interesting topic: I think many people – and especially courts – would be actively disinclined to trust an anonymous blockchain but might be interested in one where it’s identified participants with reputations, liability, etc. Pay the USPS, Western Union, etc. and get a signature backed by insurance.

Trying to explain something like Bitcoin just seems like you’d have a hard time meeting reasonable doubt standards in a dispute but that’s not the only model.

Exactly, most people have done so for centuries. Of course with 99% reliability only, but no one cares about the 1% possibly added by blockchain (with a retarded additional computing burden to deal witg).

Publish a hash somewhere you can prove a date later, like a newspaper or w/e. Then if at any point you publish the text producing this hash you've just proven you had the text at the point of publishing the hash. Blockchain not needed.

Or a letter to a fellow scientist:

In July of 1610 Galileo was still making discoveries faster than he could publish descriptions of them. On the 25th he discovered that Saturn was apparently situated between two smaller companions that always moved together. Wanting to establish his priority of discovery, but not yet ready to reveal what he had found, he sent to Kepler (and others) the following jumble of letters, which he informed them was a coded description of his latest discovery (...)

http://www.mathpages.com/home/kmath151/kmath151.htm

Yeah, crypto hype in fake technological improvements is part of this mess. People actually think there is intrinsic value in a public ledger (there isn't).

Cryptocurrencies have proved popular for drug dealing, extortion and speculation/gambling. They will probably also help with tax evasion and money laundering. Those are applications of a sort if not very positive ones. The decentralization is necessary to put the above outside government control.

Yeah but you're not seriously saying that the killer app that everybody is waiting for in crypto is " being useful for criminals ". If so it will be banned everywhere soon like in China and blockchain is just dead.

The applications are projects that require immutable data and wide distribution. Those developments haven't really been made yet.

Most of the discussion today about crypto developments is centered around bitcoin. But just because something utilizes a blockchain doesn't mean it has anything to do with bitcoin. Bitcoin was the first popular application built on top of a blockchain, and arguably the most radical.

It allows you to opt out of the monetary system that's been imposed on you by your govt. This might be less of a big deal if you live in a developed country but it's a big deal if you live in an unstable country.

Why not just hold most of your savings in dollars, euros, swiss franks, or whatever? Doesn't that just as effectively opt you opt?

Say hypothetically you lived in a place like Cuba where the government had banned things like renting out a room to foreigners or selling them a coffee as was the situation when I was there. Taking payment in the local currency would be kind of useless as you couldn't buy much with it and taking dollars, euros or whatever was illegal and could get you in prison if they caught you. However if your customer transferred some ether to a wallet you controlled with a private key but without your name on it it would be quite hard to catch or prove.

Why would it be quite hard to catch or prove? How many fiber optic lines do you think go to Cuba? They could lock down the internet the same way China does. Maybe they haven't gotten around to it yet, but that's not a long term structural argument for the utility of cryptocoins its a temporary moment-in-time argument. Kind of like how at one point a big advantage of buying things on the web was that you didn't have to pay sales tax -- that's not anything inherent in the web, it was just an artifact of governments' lag.

Say your customers are us tourists and they send from a coinbase account to some ether address. Dunno how they'd track that.

I don't think it's a lag thing - decentralized cryptocurrencies are just hard for governments to stop. Similar how governments would like to stop people paying cash in hand and avoiding tax but have never really been able.

Let’s say you have to leave the country with all your saving. I’d much more comfortable carrying it in btc than cash.

You don't need to hold physical cash to hold USD. You could have a bank account in London, Geneva, Paris, or New York with your pounds, franks, euros, or dollars. If you need to leave the country, your savings are already outside of it. Just like your bitcoins.

The answer seems to be that repressive countries haven't yet put in place effective mechanisms to be repressive with respect to bitcoins. But there's zero reason intrinsic to bitcoin to expect that to continue. On the contrary, since everything is digital the choke points are easier to control, not harder.

How are you opening a bank account in a foreign country as a citizen from Iran?

There are use cases for big money transfer and just "storing" money in BTC, not really for daily transactions.

Good luck opening a bank account in Geneva as a US citizen. Unless you bring really a lot of cash they won't touch you with a 5 ft pole.

If you consider the US an unstable country, I don't know what to tell you.

Not what he’s saying. You can’t open an account even if you are from the us, much less so Iran.

"Much less from Iran" misunderstands the problem with opening an account from the US. Swiss banks don't want to subject themselves to the long reach of the United States government's aggressive criminal justice system. That's the reason they won't open a bank account for a US system anymore. See, e.g. https://www.swissinfo.ch/eng/tax-evasion_us-programme-nets--...

The reason it was impossible, until recently, for an Iranian to open a bank account in Switzerland was not because of the Iranian governments, it was because the Swiss bank was afraid of running afoul of the US sanctions regime. Because those sanction have been lifted (at least for now) an Iranian can open a bank account in Europe, albeit they'll still have to go through a fairly extensive KYC process.

ofc But even opening an account abroad could be tricky.

The thing is that restricting bitcoin is really hard.

Especially if your hoard is ill gotten according to the laws of most countries.

Instead you can put your money into a pyramid scheme run by gangsters.

Kinda like the banking system?

Better the devil you know. FDIC and SIPC instill a lot more confidence in me (and every single rational investor) than uh Bitfinex or Kraken.

Store it in an offline wallet.

You can't opt out of the monetary system that's been imposed on you by your govt, because your govt's desires are backed by the use of force[0]. Short of moving to a different country, paying off the enforcers, or going into open rebellion, everything else is a fantasy.

[0]: https://xkcd.com/538/

You can opt out to an extent by doing stuff offshore even without crypto.

That’s not an option for most people and it has huge risks. Try buying anything big with no disclosed income sources or living well beyond your means and you’ll be getting caught by the people looking for drugs dealers, smugglers, etc. Most countries are pretty good at that.

Yes, the gist of it is, you are not beholden to the monetary system if you have a lot of money. Tautological isn't quite the right word for this.

So does foreign currency