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Comment by chris_wot | Hacker News Reader

Well, he has a point. Unless you use a cryptocurrency, I can't think of anything that needs the blockchain. I have seen plenty of people trying to shoehorn the blockchain into areas that don't need it - goods distribution, electricity supply, you name it and someone is trying to do it. Almost all of those things would actually work better with a centralised database.

The Blockchain is an awesome technology for an incredibly niche market. So his article is right - in most cases, you probably don't need a blockchain.

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agreed! I don't think there's any particular application outside cryptocurrency that I would strongly defend as "needing" a blockchain - then again, I'm not the most imaginative person, so I think others will eventually come up with some genuinely unique and valuable uses!

It's not really "needing", but one of the strong use cases is disrupting escrow. If domains, car/house titles, etc. existed as blockchain objects then they could be sold securely with no escrow.

so you can lose the deed to your house because it gets hacked..?

Physical deeds are forged all the time, and sorting it out requires a quiet title lawsuit. A stolen electronic deed would be handled similarly. You would ask a court to declare the stolen title invalid and issue a new one.

so if the court is doing that, then we have a centralized power... the opposite of the idea of blockchain.

Just to make sure it's clear, I'm not saying that courts should have any special power to manipulate the blockchain, just that they could declare a stolen title invalid, and issue a new one in the form of a new colored coin on the blockchain.

I'm not claiming any benefit related to government control, just that escrow would be unnecessary.

At which point the blockchain is not needed.

A centralized source will be held accountable to the legal demands, thus as trustworthy as the blockchain yet significantly more beneficial for all users in terms of speed, storage and utility.

I give you one shining example. Secure and untampered voting.

Let's say you record voting based on SMS for American Idol show in MySQL database. Singer A got 1000 votes, singer B got 700 votes. But singer B is more viral and popular in social media. You think if singer B goes to the next level, it will increase the rating of the show much more compared to singer A does. So you decide to bump up the singer B's voting number to 1100.

Blockchain can prevent this malicious behaviour.

Not a good case for shared write access. Just shared read access. DB's come with their own logs. If one wanted to provide verification one only needs to provide logs that other people can read and maintain diffs/copies of

You can’t prove that logs haven’t been tampered with, though. The running system is a black box that could be doing anything to that file before making it available.

This is quite simple. You simply have the running system constantly have the file or data be readable to the public. Now anyone can prove that the logs haven't been tampered with. Even better, you can just use a merkle tree data storage solution like Git to make that verification easy and fast. See Certificate Authority for a fully fleshed out solution in this nature. (I guess you could claim that merkle trees are blockchains, but in that case I would argue that the word "blockchain" is pretty meaningless. Just call them merkle trees.)

But it's turtles all the way down. How does the public know that they're getting the data and not a surrepetitiously modified version? At some point you're relying on the system to be truthful about its contents.

Honestly you brought up really valid points. Thanks. That got me thinking a plenty :)

It also effectively hands your vote over in cleartext to the nation state. There's a damn good reason why Russia is looking into blockchain voting, and it's not for the purpose of protecting fair and free elections.

Paper ballots work fine and have amazingly low error rates, leave it be.

Paper ballots is overkill for American Idol voting, though.

FYI, the voting in blockchain can be anonymised.

Maybe for pointless votes like American Idol or Formula E fanboost that's fine, although it seems like massive overkill to me. You're still going to need to justify the energy bill/incentivize miners, and these systems have a central authority that could run a regular voting system anyways.

The issue I have with electronic voting of any kind is that it's a huge and valuable target, it's pretty much guaranteed that multiple hostile nation states will want to poke holes into these systems. Introducing crypto doesn't do squat to prevent all sorts of nasty problems, including information leaks and stolen private keys. Given what we know about how most people handle basic passwords, I think paper is probably the most secure form of voting we've ever seen.

For us, American Idol is pointless. But for the singer who got robbed the championship, it's not. Yes, I admit the energy bill is part of the blockchain scalability issue. But blockchain is still in infancy. There is a room for improvement regarding the energy bill.

The political voting is a complex beast so I am not going to comment on it yet. My main focus is for the voting process like American Idol, choosing moderators in forum.

Blockchain is nowhere close to its infancy. It's a 10 year old technology.

If the voting is anonymised, then how do you protect against Sybil attacks?

When you think through this, every voting system has a weak link in terms of verifying who is a valid voter. So you must have a centralized authority here. Thus a blockchain is useless.

I edited my comment. I misread your question.

This is the hypothetical solution. Let's say there are 1000 voters. You premine 1000 coins then send it to each voter. Voter then can vote with 1 coin. So you can make sure the voting process is valid, and you can hide the sender in the smart contract. Of course, the technicality is not this simple. But you get the idea.

Anything where chain of custody is important is a great application in my humble opinion. Currently a huge problem in engineering is guaranteeing the legitimacy of parts. Everything from electronics to commercial jet parts have knockoffs being made and passed off as legitimate. If you have unique QR codes for each part from the manufacturer you can use a blockchain to track chain of custody of the part.

Beyond that you can make something unique digitally and hash it and someone can "own" that digital thing, instead of money it can be items in a game or art or anything really. A musician can make a song for a single person and sign it into a blockchain and you can prove who it was for. Lots of neat applications that haven't been created yet just like the internet when it was new.

A centralized database run by the manufacturer would accomplish the same thing. The number of trustless use cases, where blockchain really shines, is just not that large. Decentralization has a huge cost and most of the time it’s not worth the overhead.

In a centralized database it is allways possible to cheat. I think something like qualitiy data from a factory. Once you stored the data, there will be no way to change it later.

Why would a vendor cheat in a database that contains only a list of legitimate parts from the vendor? It is in their interest to sell those parts and not have any knock-offs sold.

The same goes for quality data, mostly because even if the vendor provides it, basically any industry partner will absolutely insist on doing sample tests on the quality anyway. That also doesn't remove the factor where the quality results are cheated before being put on the blockchain.

A blockchain is not very useful when

A) all participants are trusted or

B) there is no incentive to cheat or

C) if there is incentive to cheat there are already countermeasures available that are more useful (ie, doing samples and having a contract that specifies damage payments in case quality does not match)

I think the point the earlier posters are trying to make is that if a manufacturer is at a point where they need an immutable, decentralised quality record their problems are bigger than the record keeping. As someone buying parts you generally want to trust the manufacturer you're buying from, as someone making them, if you're at the point of making crap and faking records your days are probably numbered anyway.

If you somehow managed to persuade an industry to get on board, for the most part, those with nothing to hide are the ones a decentralised quality database is the least useful for - anyone trying to hide anything (manufacturer / buyer) is going to avoid taking part or cut corners anyway.

As noted by other commenters, in most of the immutable data use cases that I have seen, these ignore the much greater business and operational risk placed in your counter-party. For instance, I place far more trust in an airline to get me from A to B alive and safe than I do for them to honor the fact that they issued me a ticket. We've already established a much higher level of trust based on profit (i.e. dangerous airlines lose customers) and thus a blockchain doesn't really add anything.

Since you have to, at some point, trust the manufacturer that they built what they said they built, there is no point in a "trustless" system.

Second, you have yet to actually provide any motivation for end clients to spend money or hardware on a manufacturer's blockchain. Chances are the manufacturer would have to maintain all the miners, which is silly.

Third, the manufacturer in this case would have all of the signing keys, since they're the only ones that can make parts. This also damages the selling point of the blockchain.

So no, this does not work.

How is this any better than the manufacturer just maintaining a database of legitimate parts (identified by QR codes) and then contacting the manufacturer when you want to know if a part is legitimate? About the only thing a blockchain would do is insulate you from the manufacturer's API going down. But even that can be solved by having the manufacturer simply send you a copy of the database periodically (and then contacting the manufacturer if your database copy doesn't have the part, in case it's newer than your database, although even that can be solved by having the manufacturer generate the codes in advance, so the database they give you can already contain the codes that will be used for parts manufactured over the next month).

Heck, you don't really even need a database for this at all, come to think of it. Just have the QR code contain a signed copy of the part identifier. You can validate that the signature matches the manufacturer's public key and that will be just as good as asking the manufacturer if it's valid.

Also, now that I think about this, this whole scheme (including using a blockchain) has the fatal flaw wherein a knockoff can just copy the QR code from a valid part. There's nothing stopping anyone from reusing the QR codes, and the knockoff will appear just as legitimate as the original.

With a blockchain the end user could tag the part hash as being installed and you could see exactly who each supplier had the part at what time. A database could go offline and stop a part from begin installed into a jetliner but a blockchain would be always available. The manufacturer could track which parts the end user has in stock and installed and make production decisions easier. A consortium of manufacturers could use the same blockchain for all their parts. I am not claiming it's more efficient for all use cases just that there are some distributed trust applications that seem to make sense.

The only interesting part here is the behavior when the manufacturer's API goes down, and that's solveable just by having the clients maintain a queue of their failed modifications and retry them later when the API goes back up again. And of course the manufacturer can even provide the software that does this to the client so the client doesn't have to do any work for it.

This little subthread is a great example of a kind of fallacy that seems endemic amongst blockchain believers. "A blockchain solution X can solve problem P, therefore blockchain is useful". Without asking if there is a non-blockchain solution Y that can also solve P, and if so, what the relative merits of X and Y are.

Given that a blockchain is just a distributed database with a distributed certification mechanism, you can generally immediately construct a couple of non-blockchain solutions by first removing distributed certification, then distribution of the database itself. You can then quickly see the eigenmerits of those kinds of distribution for the problem at hand. I have yet to see an example where they are positive.

Wait, so, if I used blockchain I wouldn't have to

maintain a queue of.. failed modifications and retry them later when the API goes back up again.

neither would I have to

provide the software that does this to the client so the client doesn't have to do any work for it.

You're literally describing a benefit of blockchain. Its right under your nose.

maintain a queue of.. failed modifications and retry them later when the API goes back up again.

Your blockchain client still has to have a queue of transactions to be submitted, as the Internet is not magically reliable.

You're literally describing a benefit of blockchain. Its right under your nose.

It is a benefit of the blockchain, in the same way that transporting people is a benefit of a dump truck. That doesn't mean it's appropriate for that job.

There are many, many tools for storing and pushing messages to remote servers. The blockchain clients can do it, but it's absurd to use them unless you need the rest of the blockchain stuff. Even an email server (MTA) would be a better option.

The blockchain solution can gives more benefits more than "when the manufacturer's API goes down".

So there are 3 actors in supply chain: manufacturers, retailers, and consumers. In your solution (centralized database and API), you rely on the goodwill of the manufacturers which is fine (I guess) in most cases. But retailers and consumers have good reason sometimes not to trust the manufacturers. Vice versa.

Okay, let's consider this case: the manufacturer produces milk packaged in a bottle. So they put QR code in the milk, and put some information in their database. Let's say they put the production date into this database.

QR code: Abbbccc Information: produced on January 5th 2018

They send the milk to the warehouse A. Warehouse A keeps the milk for a night before sending to the retailers. But alas, there is a storm preventing the warehouse sending the milk to the retailers. So 1 week later, it delivers the milk to the retailers. Warehouse A informs the manufacturer about the incident. But let's say this milk only has 10 days before it hits expiry date after the production. Manufacturer decides to lie to the retailers. They updates the database.

QR code: Abbbccc Information: produced on January 11th 2018

In blockchain, this corruption can be prevented.

The blockchain is not what prevented that; the manufacturer publicly publishing that information is what prevented that. The fact that they did so to a blockchain is irrelevant.

Say the manufacturer instead just has an RSS feed on their site, where they publish that information (digitally signed, of course) as the milk is produced. The retailers just have to keep a local copy of that feed, and so they can detect any later tampering.

And if you really love the blockchain, you can always run your own blockchain that simply records snapshots of the manufacturer's RSS feed!

</sarcasm>

That said, this does bring to mind one genuinely useful aspect to the blockchain I forgot about, and that's the fact that Keybase uses the bitcoin blockchain (IIRC) to periodically record the Merkle tree roots that they use to verify their own information. The only reason to do this is as proof that they're not tampering with the Keybase history that they publish, and so fundamentally this is just the same thing as digital notarizing that I did mention before (except in this case it doesn't matter whether the courts recognize it as being valid). And you could still accomplish this without a blockchain simply by having a neutral third party agree to keep a record of the merkle tree roots, but this is one of the few cases where the 'trustless' aspect of the blockchain actually is useful.

Though of course even with a 'trustless' blockchain you still have to trust the chain itself. With Bitcoin, you can assume nobody's managed to execute a 51% attack against the chain (at least, for the time being; AIUI with the way things are going it looks like the Chinese government might be able to do it by exerting pressure on all the Chinese miners), but if you're running your own chain, how do you make mining the chain popular enough to prevent attacks?

In fact, to my mind, the only real benefit of Bitcoin at this point is the fact that it's so popular it's hard to attack (well, except by the Chinese government).

Yeah, as long as the cryptocurrency speculators are paying for it, getting a public timestamping service for almost free is nice.

I'm not actually a Bitcoin/blockchain hater; I can't avoid having a soft spot for any tech that makes me feel like I'm living in a cyberpunk world :) What I dislike is the mania. Bitcoin is a cool experiment, not a production-ready solution to anything.

Which of those examples needs to be distributed?

I'm just waiting until Oracle offers something called "blockchain" in their database products. That way you can have the buzz, without the fuss.

https://www.oracle.com/cloud/blockchain/index.html

bonus points if you can work out what it is.

You can't think of anything? There's a half dozen use-cases that immediately come to mind that aren't possible without a blockchain.

One obvious use case is collectible items for games. People spend thousands on games like Hearthstone or Clash Royale. Imagine if the cards you collected in such a game were ERC20 tokens. Instead of all that value being locked up within Blizzard or Supercell's servers, you could freely trade or sell your in-game items. I think that would encourage players to spend even more money on these types of games, and could open up huge new marketplaces for digital goods.

But if the game company wanted to make them tradable, they already could - see TF2. And if they don't want, they're also not going to implement a game with ERC20 tokens.

A marketplace where none of the money is going to Blizzard or Supercell. Where's the incentive for them to do this?

There's also a lot of technical issues here. What happens if I sell a card while I'm in the middle of playing a game?

And of course the usability issues. What happens if I get hacked and someone steals all my cards? Blizzard / Supercell would have no way to make things right short of giving out free copies of cards to people (which would quickly become an avenue for fraudulently duplicating cards by having various accounts get "hacked"). And more generally, in order to participate, I need a private key that I keep secure. What happens when I lose that key, because I'm not a crypto nerd but am just an average computer user playing a game? Now I've lost access to everything I spent my hard-earned money on, and once again, Blizzard / Supercell would have no way to make things right (short of giving out free copies of cards, which leads to fraud, etc).

About the only benefit here is the ability for users to trade items without the involvement of the company in question, but there's very little benefit to the company to allow that, and it carries far too many serious issues.

> What happens if I get hacked and someone steals all my cards? Blizzard / Supercell would have no way to make things right short of giving out free copies of cards to people

The blockchain is a distributed public ledger, but everything in the actual game itself is controlled by the game developer's centralized servers.

The provenance of any token can be known just by looking in the ledger, and the game's developer could simply blacklist that token on their game's servers, rendering it useless.

The blockchain does next to nothing in this game token scenario. It's still mostly a centralized system.

> About the only benefit here is the ability for users to trade items without the involvement of the company in question, but there's very little benefit to the company to allow that, and it carries far too many serious issues.

Exactly. Although, given that you can't use the tokens when the game servers are down, being unable to trade them when servers are down is probably not a big loss.

The moment you say "centralized" you can throw away the blockchain and save a ton of electricity.

I agree. It's a good example of chris_wot's point. The blockchain is almost entirely superfluous for this.

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