HACKER Q&A
📣 laurensr

What are real-life useful use-cases for blockchain (not currencies)?


I am sometimes overwhelmed by people's enthusiasm when it comes to blockchain. I have seen a project using Hyperledger [https://www.hyperledger.org/] as a plug-in alternative for an RDBMS but one party controlled the one node the system ran on.

Do some of you have non-confidential (useful!) use cases for blockchain databases to share?


  👤 sebmellen Accepted Answer ✓
The biggest use case I have found of blockchain tech is timestamping, especially in a case where the timestamping party cannot be trusted to act honestly because of conflicting interests.

I'll give you an example, from one of my startup's enterprise customers. This company needs to ensure that their high-end auto inventory remains in the same state through transport — the mileage, the car body, etc. They've had issues with transporters taking these high-end cars for joyrides, and it's hard to detect when this happens.

Our solution lets the transporter timestamp the odometer reading and car body with photos at time of pickup, on a blockchain. When the car is dropped off, it's just a matter of comparing the blockchain record with the car's actual state. Our system lets many parties who don't know or trust each other view the same "shared state" on a public blockchain ledger (Stellar), enforcing between these parties.

We provide a similar service for researchers who want to prove they were the first ones to make a discovery. You can read more about that at https://assembl.net.

Edit: You can try our timestamping app (still in beta so excuse some kinks) online at https://app.assembl.net. I would love to hear your thoughts!


👤 60secz
Proof of work solutions to byzantine fault tolerance are vulnerable to 51% attacks almost by definition, so if there's a value to the data it needs to be backed by a stronger economic incentive for "virtuous behavior". Doing this outside of money is problematic.

The other option is private blockchains with limited, authenticated accounts, but then why not just use a timestamped db?


👤 scubbo
(Disclaimer - I believe myself to have a better idea of what a blockchain is and how it works than the average layman, but I'm certainly not an expert)

Having recently completed a house purchase and waded my way through reams of paperwork in the process, I'm stunned that there's no "document provenance chain" implementation. At every stage of the process, I was presented with tens or hundreds of pages of paperwork that I was expected to sign, most of which was exactly the same as the paperwork I had approved in the previous round, with changes only on a page or two to reflect the renegotiated terms. However - I had no proof of that similarity, and so I had to read through every page to verify it for myself. If I could have had a programmatic way to show that a) changes only occurred in the following places, and b) the original document that I reviewed is the same as a blessed authoritative template provided by some trusted independent party, the whole process would have gone a lot faster.

Actually, now I come to think of it, this wouldn't even need blockchain - it could just be Version Control, right?


👤 Canada
The use case is money. That's it. All valid use cases involve a transfer of stored value. (eg. money, securities, collectable stuff)

For everything else there's a much cheaper option, even for time stamping. Anything involving "proving" something, meaning making some assertion at some time is not a good case. For those look at certificate transparency for a better example of how to handle that. When people say "storage", I say no. All valid cases which involve that are really about the handling of payment for storage, not the storage itself.


👤 dgrin91
Broadly speaking blockchain only solves a singular problem: Trust. If there is some work that needs to be done between parties and you don't trust the parties involved then you can use blockchain to do the work in a trust-less setting. This is why money has been the first and most prominent use case; people are less trusting with their own money.

For a specific non-money potential use case of blockchain I would say identity services. For example, currently the internet runs based on implicitly trusting a set of root CAs (hundreds just counting the big ones!). The CAs certify that a site is what it claims to be. But if the CA becomes malicious (either through intent or hack) there are limited mechanisms for combatting this.

If you decentralize the certification process you can have a trust-less system. This also works beyond CAs - any sort of identity management falls under the same principle: Credit scores, citizenship, etc


👤 Fnoord
Blockchain is extremely useful for one thing only (and, like Unix philosophy, it does it particularly well): scamming.

If you want to learn about examples, read throughout the comments. I've read about half the comments and, to no surprise, not much of substance.

Distributed DB ("private Blockchain") has its uses, but it isn't publicly owned like a traditional Blockchain.


👤 throw0101a
NISTIR 8202 in Figure 6 (p.42) has a nice yes/no flowchart to determine if blockchain or something else is more appropriate (PDF):

* https://nvlpubs.nist.gov/nistpubs/ir/2018/NIST.IR.8202.pdf

* https://doi.org/10.6028/NIST.IR.8202

The DHS originally created it, but I can't find a definitive DHS source. Also here, at bottom:

* https://www.fedscoop.com/blockchain-for-government-technolog...


👤 vmception
The consensus models without the payment mechanism all undermine the utility of a blockchain.

Proof of Work and currency are inseparable, it is all interrelated to the design of any application using the blockchain.

I used hyperledger and even the example projects from the instructor were talking about all the threaded operations it can do, if there is no cost to the computation then randoms are DDOSing all the nodes in the system for no reason, which is exactly what happenes in real world hyperledger consortiums. Its dumb.

Either accept that speculation is a use case or move on.


👤 rogerdickey
Probably none or we would have seen one already after 10k smart people spent 10 years looking.

👤 RichardHeart
You can put the word in your corporate press release for a price pump. Lol. As blockchains are the worlds most expensive and slow databases, that also have silent bit-rot... You must run your own computer that verifies that what you've written stays written, and doesn't get forked away, and that it even wrote in the first place, as the block could be full or your 1st block you are "in" gets orphaned.

Thus, you must really, truly need censorship resistance to accept that sucktitude. So what are people censoring? Financial transaction, social media posts (but they must for moderation anyway.) Websites are also censored, which is layer down the stack from social posts, The low throughput of blockchains makes them inappropriate for this purpose. Probably also for the social posts as well. Good luck!


👤 Geee
Decentralized and private cloud data storage: https://sia.tech

The benefit from using blockchain is that your data will be safely replicated and accessible from the cloud, and at the same time you are the sole owner of the data. Only your private key can access the data.

In this case, blockchain also facilitates a decentralized marketplace for sellers and buyers of data storage.


👤 neilv
The overwhelming evidence is that the primary application of blockchain is investment scams.

👤 netman21
Lotteries. Government monopolies aside, the problems with lotteries is trust. How can you be sure the organizer really pays out the winnings to the ticket holder who bought the winning number. In a public ledger you could verify all that and still keep the winner anonymous.

👤 alex_young
All the timestamp implementations seem oddly complicated for an append only filesystem. We’ve had write once media for thousands of years haven’t we?

👤 oneplane
Distributed non-repudiation; useful for inter-org or inter-political timestamping/handshaking and maybe even intention/confirmation registration.

In can do some of the things you'd use a notary for.


👤 ghaff
A general use case is where there's a group of agencies or a group of business partners who may be all reasonably trustworthy but they are in separate trust domains. It can be generally useful for all those entities to have access to a single source of truth that can't be altered without the alteration being obvious.

You can do this by appointing someone as a trusted authority. But, in practice, this has overhead and no one is completely trustworthy at least absent a lot of overhead. You also often have to deal with reconciliation when there are a bunch of different data stores scattered around.

BTW, Hyperledger is the overall foundation of projects. Hyperledger Fabric is the most popular blockchain platform under the foundation. (There are also various libraries and so forth.)


👤 AdrianEGraphene
I use blockchain to pay people to block phone spam.[1] It's also the subject of my patented algorithm on killing phone spam by requiring a refundable cash deposit for non-contacts phone calls. [2] I wrote a short white paper on this theory too. [3]

[1] https://myrobocash.com/ [2] https://uspto.report/patent/app/20200304647 [3] https://drive.google.com/file/d/1c1GyiVVZFDiUuxWkBCQ63qLdJgP...


👤 GartzenDeHaes
The biggest use would be for Automated Clearing House (ACH) funds transfers. Right now, banks receive and send money by sending flat files through a distributed processing system with no database transactions, verification, or transfer history. Some big bank robberies were committed a few years ago by compromising the banking systems that create and process these files. Once the file is sent to the ACH network, reversing transactions is a manual process and is nearly impossible after the funds leave the destination to a 3rd party.

👤 jkepler
Censorship resistant chat based on the lightning network. See https://www.getjuggernaut.com/, https://sphinx.chat/, or chat function integrated in OpenBazaar's Haven app (https://gethaven.app/faq/). This tech can run on bitcoin or lightcoin's networks, if I understand correctly.

Another example would be decentralized governance. The bisq.io project has built a system on top of bitcoin to incentivize and pay for their project's future development. They chose their model for censorship resistance (as they have concern that nation-states might not take kindly to a peer-to-peer permission-less bitcoin to fiat exchange) and its been functioning since April 2019. In historical perspective, the bisq network has innovated a new way for humans to work together that rivals the invention of the joint stock corporations by the English and Dutch at the start of the 17th century. There's lots of talk of decentralized governance on top of Ethereum, but so far the only really resilient and decentralized project I've seen in the space is the bisq network. Bisq is the sort of new thing that can be built on top of bitcoin's trust-decentralizing monetary technology.


👤 steindavidb
Do you mean blockchain or technology inspired by blockchain? Lots of cool merkle tree stuff (trillion, certificate transparency); also several international shipping supply chains use blockchain for chain-of-custody (txns are irrevocable cosigned transfer of custody with no trusted overseer). I would love to see criminal evidence and deeds of ownership move onto a similar framework.

I expect digital ID will also benifit from an auditable, immutable log (e.g. sovrin)


👤 josalhor
I have thought about this a lot. I think there exists a finite set of properties your problem needs for blockchain to be an effective solution.

First of all, you need multiple sources of truth. i.e. Everyone can make transactions with money, therefore everyone is a source of truth.

Second, you want to solve your problem in a distributed fashion and you need to figure out the incentives for each node that contributes. i.e. Everyone wants to participate in the economy and is okay with giving a small commission for a transaction.

On top of all this, you also want to maintain some invariant. i.e. Transactions do not create money.

I have thought of more properties, but they are much more boring. These are enough to throw away pretty much all the hype around blockchain. Every time someone suggests blockchain to solve a problem ask yourself if these properties apply to the problem at hand.

Example: Someone suggests logistic company x could use blockchain in order to keep a log of their distribution. But then, you astute reader ask yourself: If a single company essentially holds all the information, there are no multiple sources of truth. How would this instance of blockchain be different from a centralized database? What values does it add?


👤 CryptoPunk
Using the blockchain is extremely expensive relative to using a traditional database. The most widely used public blockchain, Ethereum, could be millions of times more expensive than AWS per ledger entry.

This is because it is designed to have its state stored permanently by thousands of computers, with any entry becoming part of a permanent canonical shared history of the network going forward.

What all of that distribution and synchronization gives you is unparalleled immutability, data permanence and uptime.

So the applications best suited to this highly constrained and highly reliable/accessible computing environment are those which require relatively small data transfer/storage, where the data operations are of extremely high value relative to the computing resources they consume.

So far these applications have been currency, marketplaces and financial contracts, which all benefit from being on an open platform that is effectively resistant to capture by any party. You're also seeing very large markets emerge in digital collectibles.


👤 forgotmypw17
I'm not sure if it counts as a "block" "chain", but I'm using a chain of hashes to verify integrity of an online message board, so that you can more easily verify that you are all seeing the same conversation thread.

And if any messages are deleted, everyone can see that something was there, and when it was deleted, and who deleted it.


👤 mectors
At Legal and General we use hyperleder to power Estuare, the first pension risk transfer reinsurance in production. Our reinsurer is based in Bermuda and given the population is only 64K and has very few unemployed actuaries, it is hard to scale the reinsurance business via hiring people. Thanks to Estuare monthly operations related to high value contracts with insurers can be fully automated and allow the business to scale. Given that the insurer and reinsurer can both introduce new data and eiter sides used to do extremely complex calculations in a spreadsheet to validate how much money needs to flow in which direction each month, the process would take weeks due to often human error. With Estuare the process now takes minutes and is fully auditable, which for contracts that can run 50 years is important, as well as allowing previous data updates to be incorporated immediately instead of once a year.

👤 BMSmnqXAE4yfe1
Blockchain is just a database that is 1) public 2) append only If you don't have mining, anyone can append to such blockchain at no cost, so it's defenseless against bad actors, so it must have a set of trusted appenders. If you want trustless public database, you must have mining. Mining is costly, so you must have a currency.

👤 627467

👤 omginternets
DNS! Namecoin (despite its cringe name) is pretty cool, and a marked improvement over DNS.

👤 bluedevil2k
Amazon’s QLDB solves a lot of issues people think they need blockchain for

👤 puranjay
One good use case I've found is file authentication. If a file is signed and it can be matched against a distributed ledger, it can help ensure the authenticity of the file. I can imagine uses for this everywhere from piracy prevention to checking authenticity of documents, records, etc.

Imagine that all land records are in a distributed ledger. The land owner has a signed certificate that can be verified anytime for authenticity. The only way to access the certificate is with a 12 word passkey.


👤 rch
The encrypted memo field of Zcash could lend itself to some interesting use-cases outside of transaction processing.

https://electriccoin.co/blog/encrypted-memo-field/

It looks like this capability is being expanded with in-band secret distribution:

https://zips.z.cash/protocol/canopy.pdf


👤 jcfrei

👤 Pamar
I arrive late so maybe someone mentioned this already: https://www.deutsche-boerse.com/dbg-en/media/press-releases/...

(Frankfurt Stock Exchange uses a blockchain as a ledger for securities lending)


👤 biolurker1
Decentralized prediction markets and derivative markets for anything. Commodities futures etc. Also tokenizing real world assets think of shares of ordinary homes.

👤 breatheoften
I'm not sure what specific technologies "blockchain databases" is limited to -- but one use case that has been bandying around me head ...

I think there could be a very powerful set of regulatory technologies created on top of blockchain style databases when used in conjunction with legally binding agreements intended to limit access to reads of the data.

Imagine a data lake for "enforcing" audit-ability of reads --

1. you may "store" some data in the lake -- say for example P2 2. if you "store" data in the lake you agree that you will not store that data anywhere else

"store" above would in actual implementation be something like storing a key for decrypting the data -- which could be stored wherever in an encrypted form and the agreement would mean "i'm not storing the key anywhere and i'm not storing the decrypting contents in any form other than as encrypted by the key".

You would leverage blockchain to ensure that all reads of the data are observable.

Obviously you can't "enforce" that the data being protected is not stored in other places or in other forms -- however the agreement "i will not store anywhere else" can be given legal or regulatory force to provide a way to punish violators.

The goal tho is to build a platform for explicitly acknowledging and communicating to both external auditors and the developers that "i'm not supposed to store this in other places". That's a technology problem which a lot of good faith implementors need help with solving ...


👤 semicolonandson
I know this question is probably intended as a technical one, but from a pragmatic/empirical perspective, the number one use-case of the blockchain is to raise money in a way that side-steps traditional causes of friction (e.g. financial regulations).

(I make no judgement on whether these sources of friction are worthwhile or not.)


👤 bawolff
Transfering (investment) money from stupid people to people telling the stupid people what they want to hear

👤 car
Check out Ubirch.com. They use firmware for IoT sensors writing to the blockchain to make data tamper proof, for example. One possible application could be the signing and blockchain anchoring (Bitcoin or Ethereum) of video from body cams, making manipulations impossible.

👤 companyhen
https://www.arweave.org/ is one of my favorites. A16Z, TechStars, and Coinbase all backing it. Really interesting tech.

👤 9985479945_
You might as well be asking “What are some real life use cases for square dancing, that are not dancing related?”

Solve problems with the best solution, don’t start with a solution and then find problems


👤 mgraczyk
This hasn't really been done, but one possibility is credibly committing to a promise about future product behavior. Imagine a company with a negative reputation for whimsically changing product goals and functionality (cough, Google). Using a blockchain allows the company to commit to a certain set of rules for product logic, regardless of which PMs take over the product 2 years and 4 PSC cycles later.

👤 zubairq
Timestamping documents via their hash

👤 neillyons
It is useful for scamming people.

👤 asymptotically3
Blockchains are totally useless without a token as an incentive to mint new blocks.

👤 wpdev_63
Filecoin comes immediately up. Decentralized github on filecoin would be killer.

👤 quickthrower2
I like the idea of DNS based on blockchain. Obviously money is involved there.

👤 lettergram
Inventory management. In many cases you want this centralized so you can manage it. But the reason is really so you have a “record” of what is in storage. The blockchain keeps it decentralized (ie less risk of a user deleting it), at the same time anyone can query the inventory.

👤 dpc_pw
Blockchain as a data-structure gives you tamper-evident, append only database.

Blockchain as a system (datastructure + PoW) solves consensus & trust between agents in a trust-less and censorship-resistant way (without introducing a trusted party).


👤 ayewo
In the long-term, I think blockchains will make a major showing in the design of self-driving vehicles (SDVs).

For SDVs to really take off, it needs to surpass the safety of a human driver but the only way to do this reliably in a way that avoids the high costs and ugly protrusion of roof-mounted LIDARs is for SDVs to use low-cost internal sensor inputs and fallback on low-cost external sensor outputs from nearby vehicles[§] and road infrastructure.

Essentially, what I think is missing from all SDVs currently in development today is an important ingredient behind why Internet-use is so widespread today: a common communication protocol between SDVs from different manufacturers.

Once a common protocol is adopted/legislated, all SDVs will be expected to record any accidents encountered during any trips in a partial copy of the “road blockchain”. Stated differently, details of accidents and near misses will be recorded with timestamps on the partial blockchain maintained by each SDV in a way that the exact position of all SDVs within the vicinity of a car crash can easily be reconstructed. Of course this will mean SDVs will use clocks that are network synced.

If 6 cars are in the vicinity of a crash between 2 cars, the trajectory of all cars before and after the crash could be reconstructed using the blockchain data from those 2 cars. If the 2 cars’ “black box” are lost due to them exploding on impact, the data could still be reconstructed using the partial blockchain data from the 6 SDVs proximate to the crash.

The “road blockchain” would be especially useful in accident investigations but its privacy implications would need to be properly thought out.

§: If a SDV has front sensors that start to return conflicting inputs while in operation due to inclement weather for instance, rather than the onboard computer aborting the ride in the middle of nowhere, it could switch to operating at partial instead of full situational awareness. In this state it could routinely query any three nearby vehicles for help: the vehicle in front, behind it & to its left to regain some level of situational awareness.

Another use case would be falling back on wireless beacons when Internet access over cellular is lost. The SDV could start an adhoc network over wireless where it can broadcast a request for help from nearby SDVs. Something like: “I’m traveling from LA-SF. I need a recent copy of the point cloud from anyone traveling in the opposite direction (SF-LA)”.

For this to work at scale, a common protocol that allows a SDV to start a wireless conversation with any nearby SDVs would be required.


👤 lisnake
Another option is gambling. With smart-contracts it's possible to build fair and auditable casinos on blockchain.

👤 bawolff
Depending on how you define a "blockchain" there are various technologies like certificate transparency or git that share certain similarities and are pretty useful.

However none of them would be caught dead calling themselves a "blockchain"

Also https://xkcd.com/2267/


👤 root_axis
Cryptocurrncies. That's it.

Edit: lots of downvotes for this comment but the evidence speaks for itself.


👤 squabble
Uncensorable Twitter

👤 kevinStorj
decentralized storage (storj.io) is a great use case

👤 chrisco255
Replacing virtually the entire financial system with code.

👤 lironmo
Blockchain technology has made headlines mainly due to the interest and attention that Bitcoin, the pioneer of digital currencies, is based on it.

The technology enables registration and tracking of the money in the system, including balances and transactions, for all users of the system at the same time. It is important to understand that if until recently the prevailing explanation was that blockchain technology has a right to exist only because of Bitcoin and other cryptocurrencies based on it, then the picture is much more rosy in terms of technology - it seems to accompany us in various walks of life.

Along with voices claiming that many resources are invested in the development of blockchain technology without the certainty that this technology will survive over time, there are many other voices heard across the globe, arguing that using blockchain technology is bringing the future to us and taking part in a revolution that will change our lives significantly .

Blockchain for food, real estate and health Thus, alongside cryptocurrencies, new uses for blockchain technology are currently being developed in various industries.

In the US, Walmart, the giant retail chain, has filed a patent application based on the use of blockchain technology that will allow the company to improve tracking of shipments in various aspects, including: location, temperature and delivery content. Sensitivity of some of the products shipped.

Other food giants, such as Nestle, Kroger and other companies in the food industry, have partnered with computing giant IBM to develop use of a blockchain system to improve food tracking.

The applications in the world also slide into the field of real estate and digital health, where developments leading to change have recently been presented, mainly in the way in which medical information will pass between the various factors.

In Israel, there are a number of companies, in various industries, that are looking to develop services and products based on blockchain technology -

Wave is developing a system that will make it possible to transfer and confirm bills of lading digitally, thus overcoming the need to bring the original document from the bank to the shipping company, as required today (a wider move is currently being made by IBM and logistics and shipping giant Marsk). Maritime trade).

QED-IT is developing a system that allows a claim to be tested in a database without revealing the content of the information itself. This allows the defense industry, for example, to test components without knowing their specific use.

BloxTax is developing a system that allows anyone to know exactly how much they have earned or lost on tokens or cryptocurrencies and to report to the tax authorities in accordance with the law, by collecting and weighting the data from the blockchain network.


👤 solresol
Mid-market insurance has a sort-of-a use case, but I've not quite been able to make it work (yet).

If you are a large-ish business, you will talk to your insurance broker to insure it. This will probably turn into a multi-thousand page document describing all the assets that you want protected, and what events you want them protected from.

The broker then does "marketing" which means nothing like what marketing means in any other context. It means that they are going out to the underwriters and asking them what parts of that whole package they are willing to underwrite, and at what costs.

The broker then cherrypicks whatever is best for their client by piecing together underwritings for different parts. ("Allianz is underwriting the buildings for the first $800m, Lloyds will do everything beyond that up to $3B, SwissRe had the best weather insurance...") The client wants to know that the broker genuinely did approach as many underwriters as they claim and validate that the underwriters did reply with the quotes that the broker claims were replied. (This is how the client makes sure that the broker and the underwriter aren't colluding.)

The end result is that across the industry there is a many-to-many broadcast and scatter and gather that needs to happen and be notarised. (The broker sending stuff out, the underwriters responding.)

At the moment, there is usually a third party hub through which these documents flow who essentially notarises the communications, but also has no incentive to allow collusion between parties. So everyone trusts that third party.

The only problem is, there is no incentive for the third party to be efficient, and so in every country / state / market where this kind of system operates, the third party inevitably takes a large cut of fees and provides quite remarkably terrible service. (Case in point: "of course it's secure, it's on port 443". "Umm, you are actually just making an HTTP connection on port 443, there's no SSL happening on this connection, as can be seen in this packet trace.")

The brokers hate how it has played out, the underwriters hate it even more. With a bit of handwaving, this is something that can be solved by a blockchain. Although the unencrypted documents themselves probably can't be on the blockchain, the checksums can be, and maybe there's a scheme where the encrypted versions of documents can be there too.

It's one of those situations that blockchains are good for: distributed system, no trust required, the users of the blockchain can afford the appropriate technical skills to keep the system running, can't be replaced by an independent 3rd party, etc. etc.

But it's not likely to happen.

The main problem is that there's no monetary incentive for any individual party to build the system. It's a tragedy of the commons problem: once it is in place, it will get used, but no-one wants to pay for it because if someone else can pay for it first then that's a better arrangement.

So yeah, five years of discussions and learning about the market, and everyone wants it to exist but no-one wants to pay.


👤 sthnblllII
What is one good use case for ice cream scoops other than scooping ice cream? One might exist, but the real question is "who is the obsession of killing digital currencies coming from?"

👤 geofft
A Bitcoin-style blockchain is a combination of two things:

1) A public ledger where each new entry includes the hash of the previous one, so you can efficiently attest to history and items cannot be silently removed from history, even if they're signed by the same participant. This is an old idea - Merkle trees are a slightly more advanced take on this idea. Present-day use cases, which are not blockchains in the conventional sense, include Git and Certificate Transparency.

2) A mechanism whereby the ability to add something to the blockchain requires the expenditure of computational power, as a way to solve the "double-spend" problem - namely, if you're storing financial accounts in your ledger, how do you make sure one person doesn't claim to transfer the same dollar to two different people? Bitcoin's innovation is to require some "proof of work" to record the operation and to make "miners" record operations (instead of participants adding things themselves), such that maintaining two branches of the ledger requires you to turn into the most powerful miner, which is computationally prohibitive.

You only have the double-spend problem if you have an object that cannot be used twice. Git does not have the double-spend problem because there's nothing wrong with having two commits branching off the same commit (in fact, it's quite common/encouraged). Certificate Transparency does not have the double-spend problem because CAs can sign an unlimited number of certificates, so if you see two different signed claims on two branches they're both valid. The two ledgers can be trivially merged together (unlike two branches of where money went).

Timestamping has the double-spend problem in its own way: either something happened or didn't happen on a day, and you don't want multiple, different records of what happened on that day. If I want to attest that something happened on June 1st, you need to be confident that I didn't make a second history that diverged at July 30 and merge it back in.

Most people do not have the double-spend problem. Fundamentally, you need a finite resource (like time or money) and you need to track the resource itself on the blockchain for the double-spend problem to exist.

A lot of people think a blockchain is useful for provenance tracking. But private records of provenance do not have the double-spend problem - you're not tracking the thing itself, you're tracking claims about where the thing was. If you see signed claims from me saying both "Lot X consists of high-grade steel that's been inspected" and "Lot X consists of faulty steel that needs to be discarded as scrap," you know I'm lying somehow. You don't need to arbitrarily pick one of those statements. (You actually don't want to arbitrarily pick one, because, again, the ledger here is just a record and not the thing itself: you want to get on my case for lying and find the truth. For the currency-itself use case of Bitcoin, it's fine to arbitrarily pick one.)

A lot of people are interested in so-called "permissioned blockchains" / "private blockchains." For the financial use cases, these usually don't have the double-spend problem because they're just a reconciliation layer on top of a slower payments system, and given a public record, you can just hold someone responsible for their double-spending, because again the ledger is just a record and not the thing itself. (This is largely similar to how "sidechains" like Lightning Network don't need to use the full complexity of the blockchain - because what they really are are records of promises to perform transactions on the primary blockchain. If someone makes two promises, hold them accountable for both.) For the non-financial use cases, you probably don't have anything resembling the double-spend problem in the first place: what you want is, at most, something like signed commits in Git.


👤 jedimastert
I tend to mentally repl

👤 samatman
Urbit has been using Ethereum to distribute scarce identities for its peer to peer personal-server network.

There have been some growing pains, but it works.

Note: not interested in explaining what Urbit is, let alone fielding tedious political commentary about its departed founder. Just highlighting a successful non-currency use of a blockchain.


👤 usr1106
I believe certificate transparency http://www.certificate-transparency.org/ is based on blockchain technology. (Haven't studied it in detail, just happened to notice this new SCT field in my Let's Encrypt certificate recently.)

👤 ghayes
For what it’s worth, you might not get great answers here. HackerNews readers tend to have a relatively negative view on crypto, and many people involved in the space thus tend to avoid discussing crypto here to avoid accidentally getting into a flame war. If you’re interested, I might suggest reading Coindesk or visiting the Discord or Telegram of interesting projects.

👤 mareko
Venmo for all.

We're used to Venmo in the US but many places in the world don't have an equivalent. Valora is a new Venmo-like mobile app that's built on the Celo blockchain, a new network where mobile devices can efficiency sync with the chain, with a native stable coin, and a decentralized phone number verification protocol.

Check out https://valoraapp.com and https://celo.org


👤 _b8r0
Usually it's when you want decentralized validation of time-series data. E.g. The egg industry adopts a solution whereby the chicken are tracked on a blockchain so people know which chickens are kept outdoors and which are indoors. The eggs are then tracked and checked in at each quality gate and the consumer then gets a QR code for an app that tells them where the egg came from and where it was checked for tampering etc.

A blockchain isn't the only solution available, and it doesn't require a public blockchain. A blockchain could work in this space for storing decentralized time-series signatures.


👤 sebbyBinx
Jewelry.

Digital assets will have their place alongside gold and diamonds in jewelry, and perhaps even entirely replace them.

A significant issue with gold and diamonds in jewelry is that the value is destroyed if the jewelry is lost or stolen. However, Bitcoin and other digital assets do not have this issue since a pointer to the value can be worn, not the value itself.

I made a site which promotes this idea in an open way: thebtcring.com

https://www.engadget.com/2015-05-21-a-bitcoin-engagement-rin...

https://m.imgur.com/kX9i80Q


👤 nradov
Synaptic Health Alliance

https://www.synaptichealthalliance.com/

Medical insurance companies have a huge problem just keeping their contact databases of healthcare providers up to date. Doctors move offices or retire or stop accepting new patients and never bother to inform the insurers they work with. This system allows competitors to share that data in a fair way which reduces healthcare costs for everyone.


👤 cynusx
I have only heard of one good use-case and I have been in fintech for the past 6 years.

Swift GPI allows banks to credit the receiving parties' account in 10 minutes rather than overnight.

It's an example where the existing party (swift) already had accumulated all the trust necessary and the consolidated ledgers were updated overnight.

Swift GPI allows a bank to track any inbound payments and recognize it to clients before it is formally received by the batch process.

In my mind it also sets the only way to successfully launch a blockchain solution... by the incumbents who already have the trust centralized and are interfacing with a very large amount of parties (8k banks in the swift network).

The best solutions in my opinion should come from governments as they often act as notaries often act as trust providers. Examples here are real-estate titles, assets and potential liens on those.

Hell, we should require the whole federal budget to be spend in crypto-dollars so citizens have full transparency of what happens with their taxes.

Governments that grasp cryptocurrency could remove so much transaction inefficiencies caused by the current registration processes and uncertainties around ownership.

Other potential solutions would be for multinationals their accounting. Their accounting of every subsidiary is in a different system and creating consolidations is usually done periodically (and expensively).

Allowing an open accounting architecture for multinationals could boost innovation and kill companies like SAP who really is the only player in town that can handle the complexities multinationals face.

A company like facebook or google could develop this and open-source it