is there any legitimate use of blockchains?

Any application where you want to record something publicly without the possibility to alter it and in absence of a central authority.

A database requires a central authority so it doesn’t cover the same use cases.

Good summary, a few additions from my side:
Being public is not required. E.g. banks could form an internal block chain shared only with other banks.
Blockchains are a database. An immutable and usually distributed database.
- Also worth noting that the computations don't have to be expensive either, it's only there in cryptocurrencies to artificially limit the number of blocks generated on a public system and tie it into the reward system.
  So for a bank, that could be a plain single iteration of a sha256 hash, and once share everyone agrees those were the transactions and you can't go back and change one without having to change the whole chain.
  Make it sha1 and you basically have git.
  A blockchain is more or less just an append-only database. Or even an append-only replication log with built-in checksums.
- I would argue against blockchains being a database... its more of a 'signed sequential log' than a database.
The lack of a trusted central authority is key. If you have at least one authority you can trust just barely enough, the whole idea of a blockchain collapses. There needs to be an urgent trust crisis for this to work.
- Also, if you have no trusted parties, you have a huge "First Owner" problem.
  If we were to set up a blockchain to track the ownership of fluffy hats, what's to stop me from seeing your fluffy hat, and quickly registering it as mine?
- It’s also a problem of ownership. For exchanges between banks, a blockchain is better because no bank would be the owner of the database.
  Plus it’s safer because altering a database is usually trivial while altering a blockchain is virtually impossible.
Could this be a true voting record? Votes would be transparent, but as you say, unalterable.
- If the political vote is public, voters are exposed to blackmail or they may sell their vote. It’s a bad idea unfortunately.
- https://xkcd.com/2030/
  I appreciate that when you find a relevant xkcd, the explainxkcd page also has relevant information to the discussion:
  https://www.explainxkcd.com/wiki/index.php?title=2030%3A_Voting_Software
  When the reporter follows the interview up with a mention of blockchain technology, Megan and Cueball reflexively tell the reporter to avoid any voting system using the technology at all costs. Blockchain is a relatively new technology that is intended to solve some computer security issues by making it difficult to doctor old data. However, in the process of solving the old computer security issues, it has introduced new computer security issues that have not yet been ironed out; for instance, it doesn't solve input fraud issues, only data-doctoring fraud, so if a program caused the voting machine to record a vote for candidate B whenever a vote for candidate A was cast (such a program could be uploaded to the voting machines through USB, or through the internet which the voting machine must be connected to for blockchain), blockchain would not prevent it. Blockchain has also had a large number of high-profile scams, thefts, and implementations with critical security holes. Thus, Megan and Cueball may not trust this blockchain solution because of this history.
  Blockchain is really great at preventing post-facto data changes. With blockchain you can somewhat guarantee that no one comes in after the election and changes the votes on the machines. (Unless they're handling the blockchain in a stupid fashion, for example without the distribution.) But you cannot prevent tampering with the machines themselves, such as making them record votes that didn't happen, or tampering the data before it's written to the blockchain.
  Also, the security issues that Blockchain solves could also be solved via write-once memory, which would be more secure and more difficult to doctor.
  Most computer security specialists are more worried about programs that randomly and/or deliberately misreport a vote, than people changing the votes after they're already recorded, so blockchain would solve an issue that most computer security specialists are less worried about, while causing new issues (the perpetual internet connection among them).
i’ll add a concrete example to this… i’ve described a startup i built in another comment but TLDR:
compliance obligations when protecting kids from sexual predators are difficult to prove: sexual abuse usually comes out 30 years later, so standard record keeping is pretty fraught… companies (like the company monitoring compliance - our startup for example) might not exists any more, paper gets lost, database formats become difficult or impossible to read
writing signed proof of compliance to the blockchain is a way of ensuring that an organisation was doing what they could at the time… how this is achieved is tricky for anyone but the source of record, but with blockchain it’s possible (described in the post)
That was.. Very well said
this was a no nonsense answer, unlike the others discussing Cryptocurrency ;~;

Anything that requires a public, immutable database. Land registry would be one example. Notary public for electronic documents would be another.

You can leverage the majority consensus to create a trusted software build system. Each block would be a package build

If you have to have someone enforce the land registry or the documents, what is the benefit of the database being zero trust?
land registry
Yes! No more need for title insurance if ownership records are clear and public.
- They already are in most countries. E.g. in Poland land registry is maintained by court system and any changes are made only as a result of court order or a filing made by a notary public, who has a real incentive to check all the documents, because they are on the hook financially for any false filings.
- But them the government can't unilaterally take your property from you for a pittance under eminent domain. Who wants a system like that?

It's just a data store (database kind of implies extra features) that's trust-free and decentralised. It's not even the only way to implement one; Ripple for example uses a slightly different scheme.

How has nobody linked the XKCD on this exact question? Randall Monroe compares them in the alt text to grappling hooks: something cool that might have uses, but only in very specific niches. https://xkcd.com/2267/

Using it as a currency which requires no third party for transactions is a legitimate use case. See current payment processors vs Steam conflict for why it may be a good idea. There are a lot of times when it's not a good idea either.

However the price must be reasonably stable and transaction cost low. Don't think any of the major CCs qualify.

Swift exists though? There is really no need for Credit cards or other payment processors.
- What's swift?
- Why can't I use swift to buy anything of eg steam? I genuinely don't know but there has to be a reason.

People will easily list a lot of credible legitimate usecases

that are hypothetical

and have remained hypothetical for 18 years.

Being on Lemmy, I like the idea of decentralized and permissionless stuff, including money. The problem I have with crypto is that they're either clearly scams (Trumpcoin, Melaniacoin etc) or they were not intended as a scam but the market fails to fairly price them because they speculate (e.g. Bitcoin).
Also I don't understand why people keep insisting in buying Bitcoin when the energy to "produce" it is enormous and is responsible for a lot of CO2 emissions when there are greener cryptocurrencies.
- @tirednbored @Deestan the mining aspect is what makes it secure.,. In theory Proof of Stake is greener, but once someone archive 51% of stake he became the owner of the network, while with proof of work the cost of securing the network is permanent... Saying this, i do agree that bitcoin energy spend is ab issue...
Yes, your honor. My buying of drugs online was only hypothetical, it never happened.

Some countries are considering using blockchain in the future for their land title registry.

here is an article about it

I read something about potentially using blockchain the future while using onland (ontarios land registry service) but i can't seem to find the page that mentions it.

There's a few issues with that approach:
Blockchains can't forget, but they also need to add new blocks on every period, meaning that there's a lot of idle events that are added to the chain. You can increase the period, but then the chain has more latency. Either way, the disk space needed to store the full chain grows really fast, which becomes a problem when trying to bootstrap a new root node, or backup an existing one.
Unless you're trading land titles internationally (read: there's no single trusted authority), blockchains could just be replaced with a regular distributed database and servers.
Chains don't offer out of band recovery and error correction.
- Totally agree. And my problem with the example of land use that a single entity (the government where the land is) will be the sole enforcer of it. So who cares if the information is slightly less centralized, when the actual product is just as centralized as ever?

In theory, yes. I can't think of a practical example, but it's basically a decentralized, public, write-only database. I'm sure there are niche applications for use as a public ledger or similar.

Honestly, cryptocurrency is an example. Some cryptocurrencies don't have mining and so aren't all that bad, and there is a use case for it, even if most of what we see today is hype.
Another example might be something like a way of proving something happened before a certain time. Like how people can send themselves sealed letters in the mail, and claim that the postmark proves that it was sealed before that date. If you put cryptographic signatures only into a public blockchain, that could be used as evidence that the document existed at that time.

Just a big scam.

The only remotely valid use case I ever head was for a Write Once Read Many (worm) audit log but regular databases are still a better fit.

Besides money laundering, you mean? Not as such.

Merkle Trees were thought up in the 70ies or so. A blockchain is a Merkle Tree without branches. They are used in a number of application; for example git which predates bitcoin.

The actual innovation behind bitcoin is mining. A payment system needs someone who runs it. Bitcoin introduced a way for these people to get paid by creating new currency for themselves. That way, there is no single entity in charge. There is no contractual relation that would require government enforcement.

If a Merkle Tree is the only thing a blockchain is to you, then it has legit uses. But that was already widely used before a simplified version became called blockchain.

If you're thinking about a bitcoin-type blockchain, then evading government oversight is its sole use. The technical overhead and the economic inefficiencies exist only to obscure identities and legal responsibilities.

It was an innovative way to use a blockchain/Merkle path, too. Even if you'd argue money but made in a different, harder to police way is a bad thing, it was new.
- It's really clever. I also think it was unintentional. They did not want to create a money laundering tool but a currency in its own right. That failed.
  Also, this scheme only works with money involved. The miners run the system, and they get paid by creating new coins. If they cannot sell the coins to cover their costs, then there is no blockchain.

Yes. Tracking stock shares would prevent dark pools and naked short selling to some degree.

That's also why it will never happen.

The point of the blockchain is to achieve distributed consensus of what's in the database. That way, one entity can't unilaterally change what the database says.

If you have a public non-profit institution maintaining the database, obligated to serve all legal customers, with serious consequences for tampering with it, you can get pretty much everything blockchain can do, for a billionth of the computing power.

But with that system, you would lose these features:

partially-anonymous participants
service of all customers, even illegal ones
immunity to court orders

Basically, no. At least, not until everyone has the knowledge and resources to run their own compute, which is never.

Decentralized systems must be accessible and maintainable by the majority. Blockchain is neither of these. It's also why the internet moved to platforms rather than remaining as many niche forums.

Additionally, network effects and economies of scale make decentralized systems difficult. See Lemmy. Even here, World is the biggest because it's simpler and easier to do everything in one place. People don't have to make decisions. People don't have to do their own work.

Basically, human psychology and economics suck

Not really, blockchain technically has been around for almost two decades and there still isn't a good use for them. It's very interesting piece of tech that could potentially be useful, but still isn't in a practical sense.

Think of it this way, blockchain tech is a solution looking for a problem to solve rather than the other way around.

Yes. Public append-only data structures. For example: https://en.m.wikipedia.org/wiki/Certificate_Transparency

No. From the most base concepts, some authority still needs to recognize and enforce the contents of the blockchain (ownership, currency, whatever). If an authority is already trusted to act on this data, they might as well be the secure custodian of it. Or, if not entirely trusted, a third party trustee. At very best the blockchain offers complete transparency and auditability, but this is the trust you place into any given system on your end. If you do not place trust in a system, what are you doing engaging with it?

Supporters of blockchain generally don't accept these arguments because they are anti-authority, and without passing further comment on that, fair enough. But that means it will only ever be relegated to buying drugs on the internet and scams.

No. From the most base concepts, some authority still needs to recognize and enforce the contents of the blockchain (ownership, currency, whatever).
What authority is needed when blockchain is used as a currency, what is there to enforce?
But that means it will only ever be relegated to buying drugs on the internet and scams.
You can buy much more than drugs using cryptocurrency, so this is absolutely false.

OpenCerts

An easy way for employers to verify that your certifications are authentic.

Tangentially, a lot of scientists do research on topics that do not see application in everyday life immediately.

I can't think of any examples off the top of my head, but I remember reading articles on how some research bear fruit - ones with huge impacts - only decades later.

To stop research into a topic because there is no practical application now is short-sighted IMO.

OpenCerts does require institutions to be trusted partners, so this isn't permissionless. Why not just make the normal database searchable if it relies on trusting someone?
It's not that blockchain doesn't have any applications. It's just that it only solves problems in ways that are easier and better solved by other implementations. It's not that are no practical applications, it's that there aren't even any realistic theoretical applications.
- it's that there aren't even any realistic theoretical applications.
  Here's the neat thing about research: the researcher themselves may not even know the kind of outcomes their research would bring about in the future.
  It is not necessarily a known unknown in which we work towards a theoretical application; it could very well be an unknown unknown.

it's really difficult to be anonymous with a credit card

since a lot of replies branched towards Cryptocurrency, which is where blockchains are implemented the most in. But it isn't the sole purpose of blockchain.

It's a distributed, append only(theoretically), tamper proof data structure. Look up merkle tree, certificate distribution, etc. These comes in different shapes and sizes for storing transaction logs, to keeping track of online identity and false impersonation.

You can implement a blockchain that might not get as power hungry as crypto block chains(because mining), and it's a cool solution in distributed systems

Blockchain has been ”the next big thing” for 10+ years without making any real impact outside of cryptocurrency speculation (which is mostly a pyramid scheme). If it had any legitimate use, it would be widely used today.

No less than 8 spelling or grammar mistakes, and barely on topic.
in the spirit of reddit:
*peddling
i think op asked for Blockchain not Cryptocurrency

Gods unchained is a digital TCG that is the only good use of NFTs (and thus Blockchain) that I can think of.

The idea of NFTs is you have a specific instance of a thing that you can trade around. NFT art is stupid, because at the end of the day it's a jpg. However, with a digital TCG, each NFT can represent a singular copy of a digital trading card. It brings back the "trading" aspect of a digital TCG, made more convenient than physical cards due to digital transfers.

Could you elaborate a bit how blockchain enables something unique here? I see that it enables trade between users, but if a single company controls the game and I assume supply of new cards, does the blockchain aspect for trading really matter?
Trading itself is basic and doesn't need a blockchain. I guess with it you have it implemented in a public and tamper proof way, but that second part doesn't seem to matter to me if the source is centralized.
So what exactly is gained from this approach over just your average ingame auction house?
- i feel like the only real 'advantage' here would be that the cards couldn't be proxied which sounds like only an 'advantage' to the people on the rent-seeking end of the bargain.
- but that second part doesn't seem to matter to me if the source is centralized.
  That's the thing, it's not centralized - in this game, for the first time ever in a digital TCG, if the company hosting it closes it's doors, you still have something in your ownership that corresponds to your cards, opening up the possibility of others re-implementing everything.
  It ain't much, and it's a long shot, but for the first time ever it's possible.
No way. There are many ways to introduce artificial scarcity to digital goods, and no it is not a new or good use of the tech.... Artificial scarcity is a huge part of all of the world's problems.
- Before we start blaming a digital trading card game for the sins of capitalism, let's both acknowledge that "artificial scarcity" is built into games. Mario suffered "artificial scarcity" when he didn't have a red mushroom at the ready. Anything that requires "unlocking" can be argued to be artifical scarcity. At the end of the day it doesn't really matter because these are aspects of a game and not real world resources.
  Every digital TCG - Hearthstone, mtg arena, etc. all already have artificial scarcity.
  This is just allowing for you, as a player, to actually have a semblance of ownership over the digital goods you obtain, independent of the company you purchased it from, which is far more than any other digital platform will allow for.
How is this different from MODO?
- Not sure what that is, searching doesn't help

A database is not an alternative to the blockchain.

It absolutely can't be replaced by a simple database, saying that makes me question that you truly understand the technology. Here's the important question, who owns the database and how do you know you can trust them?

Would you trust me to manage a database that holds your money? What about someone who's actively opposing you? How about a foreign nation? That's the thing blockchains solve, a decentralized 0-trust way to have an append only ledger, yes a database can be an append only ledger, but it can't be decentralized or 0-trust, that's the important thing here.

Let me give you a very recent example, Steam has been censored, and has had to remove certain games from their catalog, this happened because PayPal and other payment providers forced their hand. This is the sort of problems that arise from having someone own the database, they can dictate what you do or don't. Let me be extra clear, this sort of censorship is essentially impossible in Bitcoin and other cryptocurrencies because no one controls the database.

Recording data on an "eternal" digital data storage is incredibly useful. You don't need much imagination here but I think we overestimated how much people actually want this and how ok we are with less perfectionist systems given that they work now just fine. Storing something on the web is usually just as good in practice despite being less perfect data store mechanism.

That being said what if we have incredibly important information that is difficult to share or preserve - an immutable blockchain with so much financial security is a really powerful tool here.

Thats what got me into bitcoin at the beginning but disappoingly it never reached the point where it would outcompete non-blockchain tech. Mostly because we live in a better world than many believe 🙃

Maybe Odysee and monero????
Those are the only BlockChain technology platforms I can think off

blockchains are a solution looking for a problem.

Sure, there are a ton of things the blockchain would be great for. Also, it just so happens that nobody uses them for that because the people developing the tech only dream about using it to join the bitcoin billionaires club.

This is it. This is the real answer. The same goes for AI. The really good uses for both aren't lucrative enough, so the people with the money try to shoehorn it into places that aren't a good fit in order to justify their outrageous valuations. Rinse and repeat until the bottom falls out of the market, then sweep up the pieces and try to come up with a new grift.

it cannot really replace a simple database. it has an integrity guarantee. not in the way that data won't get modified accidentally, but that it won't get modified onesided.

the git version control system also uses a kind of a blockchain structure. git was made by the creator of linux. a major difference is that git does not use proof of work for consensus, I think it just does not use anything for that, other than the web server's access control mechanism.
commits are built on top of a large chain of histories, and the commit ID verifies that the current state and the history of it is the exact same when you checkout that commit ID on any other computer. if you go find in the repository a commit made 3 years ago, and change that commit (this is supported by git but not recommended), either the content or the metadata like time of commit, the whole history after that also need to get rewritten to remain valid, and so all those commits will now have a new commit ID

The decentralized idea is great, but with so many shitcoins out there...it's tough.

Are you really going to build an entire car title company stop something like Binance or Trump Coin or Ninja Bits? Hell no.

I think the concept is good, but the execution thus far remains to be seen.

"Blockchain" as commonly meant as used in cryptocurrencies - no. Only for Bitcoin - all other *coins are scams.

However git can be considered to be based on blockchain so in that sense, absolutely.

However git can be considered to be based on blockchain
That’s really stretching the definition of blockchain.
Blockchain is about providing consensus without relying on a central authority. If there are two variants of the same blockchain, anyone should be able to independently verify which one is the real one. Git doesn’t do this.
- That's one definition of blockchain. Since the solution to the Byzantine Generals' problem in Bitcoin is done by Proof of Work it can't be said to be a part of the blockchain definition since there are many (most?) blockchains that don't use PoW. Some companies peddling "blockchain solutions" even use central authorities.
  So, with "blockchain" just being a chain of cryptographically verified blocks then git indeed fulfills that definition.
- No a blockchain is a chain of blocks. Its an append only datastructure that provides a cryptographically verifiable history. Proof-of-work is what allows for public concensus in crypto currencies like bitcoin, where as git uses signed blocks to identify different chains.
However git can be considered to be based on blockchain so in that sense, absolutely.
How would that work?
- I think parent is referring to Merkle trees.

What are the alternatives?
How else can you create decentralized permissionless money (you know, the thing it was created for in the first place, before people got an idea of putting monkey jpegs there)?

What are the alternatives?
https://www.taler.net/en/features.html
- So, I haven't read much about it, but right on the page you've linked it shows banks on a diagram explaining how it works. If banks are involved, it is not permisionless - banks can block and censor transactions, they can refuse to open an account for you at all, etc.

Believing all the cryptocurrency ecosystem is a scam is just a big indicator that you know nothing about it

The main thing is to have a trustless currency that is decentralized (can’t be easily censored), and that isn’t owned nor controlled by some centralized organization (ex: a country). Its uses are best seen in countries where the government goes bankrupt or fucked up the currency by printing a lot of it, or for currencies that no other country trust

It will be niche and useless to most people, but it’s a verifiable way to check money is not being tampered with. It’s also the best way to transact online anonymously or pseudonymously, and not relying on a company that’s trying to make as much money as possible

Due to the way some cryptos are, they became a speculative investment. The fact that they’re not well known increases this use. Some cryptocurrencies are designed to be inflationary. Some are straight up pump and dump scams, like a lot of things. There will be assholes everywhere

Why is mining a nessecary part? Is it only to keep the quantity of units in circulation in check? And why is that nessecary? Is there an equivalent fixed amount of USD that is in circulation?

Why can't it just be a ledger of fixed qty where nodes get paid a fee for handling transactions and keeping the blockchain updated instead of proof of busywork? Why does it need to be so wasteful of electricity? Why is it so slow? Will it ever be as fast and cheap as an osko payment? I can (and have) sent $40,000 to another person from my bank account and it took under 10 seconds for them to receive it, even though they bank with a different entity.

Lotsa questions. I'll give brief answers that will be a little incomplete.
Why is mining a nessecary part? Is it only to keep the quantity of units in circulation in check? And why is that nessecary?
Transactions need to be recorded so that it is known who controls how many crypto coins. This service needs to be paid. That is done by creating new coins or alternatively by subtracting a fee from transactions. Creating new coins has the advantage that it spreads coins to people with a stake in the success of the cryptocurrency. If there was only a fee, then you would have to find some other way to get coins to the people wanting to use them.
Crypto is for transferring money outside the banking system and thus beyond the reach of the law. People buy and sell crypto coins for that purpose.
The value of coins depends on how much money people want to transfer and how many coins are on the market. If people want to transfer $10M and there are 10M coins available, then the price of a coin is $1. If there are only 5M coins, then the price is $2. People wanting to transfer money do not need to consider the price. If you want to transfer $20, you buy that amount of coins. It does not matter how many coins that is.
When miners sell new coins, that causes a little bit of inflation. That way, real money is transferred from the users to the miners. If someone holds a large amount of coins, they can extract a lot of money without having to do anything. So people will not be very keen on promoting that currency because that person can skim off the gains. That means it's simply preferable to slowly introduce new coins to a wide audience.
People who "invest" in crypto cause a bit of deflation. They spread real money to the users but there is no actual value created.
Removing coins from circulation increases the price in a purely mechanical way. If the price rises further, they are able to make a profit by selling the coins and skimming off money from the users. That does create an incentive to promote that crypto coin. That's why we are seeing so much crypto spam.
It's not necessary for adoption to increase to see a profit. If other people can be convinced to buy and hold coins, then the price increases mechanically. This makes it possible to skim off more money from actual users than was spread to them by buying the coins. Obviously, that's economically nonsense. It's another fatal design flaw.
instead of proof of busywork? Why does it need to be so wasteful of electricity?
The record of transactions, the ledger, is public and unprotected. You could have different, competing versions of that record. The version that is adopted by the majority is adopted as the correct one. This creates a problem. It would be possible to spam the system with lots of copies of a fraudulent record. Proof of work mitigates that risk. Originally, it was an idea to combat email spam by increasing the cost of sending each mail.
A more efficient alternative would be to only allow a limited number of known entities to keep the ledger. If they attempt manipulation, they can be prosecuted for fraud. That's basically the banking system.
But the whole point of crypto is not to do that. If governments could prosecute the people involved, then they could also be made to crack down on ransomware, drug dealing, tax evasion, and so on.
A more crypto-compatible scheme is proof of stake. Miners have to put up a certain amount of cryptocurrency as a stake. If other miners find that one is not following the rules, then they can be fined. Also, because they own a substantial amount of currency, they can be assumed not to act in ways that harms the network. That would lower the price of their crypto.
Why is it so slow? Will it ever be as fast and cheap as an osko payment?
The overhead necessary to avoid law enforcement means that it will always be slower and more expensive than mainstream systems.
Bitcoin, in particular, is just not suited for such wide adoption. It's actually amazing how well it does actually work, considering its humble origins. Because of the amount of money that rests on its reputation and its decentralized nature, it is extremely difficult to get people to agree on updates.
Is there an equivalent fixed amount of USD that is in circulation?
No. Money is created every time someone takes out a loan and destroyed when it gets paid back. Physical currency (called central bank money) is manufactured as needed.
If you make more money, then you have a larger share of all the money in circulation. That means, you are devaluating everyone else's savings and pretty much gaining some of their money.
And there's some system where people who have joined through you, somehow also produce to you some small percentage of the money they mine. So, the ones who got in first are getting richer and richer out of others' work.

Git uses blockchains to store pretty much all of the worlds software...