Hacker News Reader

Comment by smsm42 | Hacker News Reader

I just have been at OSCON, and they were talking about blockchain all the time, blockchain this, blockchain that, private blockchain, enterprise blockchain, blockchain plus this thing and blockchain on top of that thing. But still I couldn't figure out or find any explanation how anything of it would be useful for the member of the public, and indeed how it can work sustainably without the hype that would drive the cost sky high and makes people invest into mining hoping to cash out one day. And all hype ends eventually...

View on HN

blockchain is useful outside the context of cryptocurrencies because it represents a verifiable chain of custody.

For example, imagine how blockchain could solve the problem of a patient who has control of their health records. In the current system we have an issue where anytime you move somewhere away from your doctor, the new doctor you see has to retrieve records directly from your doctor because there is no way to verify that the records you would present to the new doctor are the most up to date records. If your doctor gave you your records from before your last visit, and say during your last visit he wrote into your files that you no longer needed opiates for pain management, but you are addicted and want the pills still. Well if you have outdated records and take them to a new doctor you might be able to still receive the drugs, despite the fact that the doctor that initially diagnosed you took you off them. This is why most states require by law that they obtain records directly from the source. To avoid being able to scam the system.

Now imagine what happens if your doctor dies, his practice is shut down for whatever reason, or for some other reason your records become virtually unobtainable.

What do you do then? Go through the entire process of trying to get a doctor to re-diagnose you for an ailment that has already seen years of therapy and might no longer be as obviously in need of say pain therapy?

It's a problem. And something that blockchain could fix better than just having some federally regulated centralized medical record repository that in it's very nature allows the government or any bad actor a straightforward method to hack into and invade your privacy.

Blockchain allows you to maintain personal and private control of your records, while allowing a doctor to consult the blockchain network of doctors, to verify that the chain of custody of your medical history is up to date.

> blockchain is useful outside the context of cryptocurrencies because it represents a verifiable chain of custody.

Only if we are talking about the custody of a purely digital asset, or purely digital information (as in not linked to anything in the real/physical world).

> For example, imagine how blockchain could solve the problem of a patient who has control of their health records....

If you have control over your own "blockchain" medical records, what is stopping you from omitting the last few records too? How is this going to stop your data from being leaked by someone who hacks your current doctor? How will all doctors be forced to use it (if it is not put into law by a government body) and this case, why would this be chosen vs a centralised system? Who will be "mining" and why?

What happens if you are taken to an ER, and you are not conscious? How will the ER get your records if they are somehow sealed? All it takes would be some dying because of lack of access to the records for the system to be scrapped. As people would be more interested in saving lives vs worrying about governments and corporations snooping on them. Hell today we are giving up our privacy for things are mundane and pointless like Social Media.

Existing medical records systems — including those for sharing data across organizational boundaries — always include some sort of "break the glass" functionality which allows certain providers to access charts for patients who are unable to immediately consent. This is absolutely essential to real world patient care. That access is always logged and audited so it's not a real risk for patient privacy.

Can't you do the same thing with a simple chain of hashs a la version control?? Why would you need distributed consensus on a patient's health record. My understanding is that Blockchains only make sense in a low trust distributed environment... If you have that low of trust in your doctor it doesn't even make sense to show up.

I think it starts to make sense if you can hold your data and only it share it using hashes of that data without exposing it. For example, I could hold the private key to my DNA, where each strand would be hashed allowing me to share portions of my DNA data with companies without sharing the entire thing. And it makes sense to do that over a public ledger.

But the hash of health data isn't informative. It doesn't make sense for a doctor to view, for example, the hash of a blood test result. They need to see the actual result, not its hash. The same thing is true of DNA sequencing results. The only thing I could learn from the hash of a DNA sequence is that it's different from one I have in a database. But I need to know exactly how it is different -- precisely the clear text content of the sequence -- for that to be useful information for a patient or for research.

> And it makes sense to do that over a public ledger.

Why? It makes much more sense to keep the data to yourself, I do not see any advantage in making it public and intermingling it with data about other people.

How does block chain solve this problem any more than a plain old text file with your medical history?

IIUC the only thing keeping bitcoin's blockchain trustworthy is millions of people mining new coins and therefore distributively verifying the blockchain. Who would be doing that for your medical records and what would their incentive be to do it?

You need that text file signed by your previous doctors, and your new doctor needs to be able to verify the public keys of your previous doctors using some type of PKI. You also need to locally manage your health records data, its storage can't be easily automated and paid for. Blockchain solves all of those problems in one nice bundle, it provides PKI, signed log of changes, and distributed automated storage. That's one hell of a feature set.

As far as I understand the point is supposed to be the blockchain is distributed trust. The longest chain = proof of most work = the truth. The only reason someone can't basically change the entire history of the blockchain is because no one has 51% control of the chain. The only reason no one has 51% control of the chain in bitcoin is because so many people are mining it to earn coins.

But, for medical records there is no such incentive. Therefore anyone can easily change the records or add new ones and claim everyone else who has a shorter chain has the wrong chain (which will be like no one since there is no incentive to mine).

So I'm probably just informed how blockchain is supposed to help here. Without the distributed trust there's no plus to blockchain. And without the incentive to mine that generates millions of miners there is way to have the distributed trust.

I'm happy to be wrong but I haven't see an explanation how this issue is solved for all these non virtual currency uses cases.

Using bitcoin(I know less about how to store data into bitcoin transactions) you can execute a transaction and store a small piece of data that would be a reference to a larger blob of data, say an IPFS hash to an encrypted MRI image and the doctors notes. You use bitcoin to store the log of changes using reference to some type of immutable data store. It's imperfect, but can be built. The value add of the bitcoin here is it's extremely hard to create a false history and tell that as the real story.

Ethereum would be easier to understand and see what's going on because we have a reasonably readable contract language. You'd still likely need to store larger blobs of data using an external immutable data store, and those blobs wouldn't be automatically distributed and backed up. But you could pay for distributed backups in an automated way using ether. Lots of people working on this last part, which drastically reduces the potential size of the blockchain because it will only be afordable to log blob references and numerical values.

you can also send messages with pigeons, why use internet and whatsapp at all?

In practice the medical records sharing problem has already been solved by leveraging existing standards and integration profiles created by organizations such as HL7, DICOM, IHE, Direct Project, etc. Those solutions aren't yet universally deployed but they are rapidly gaining adoption and do actually work.

Sole practitioner medical offices are dying out as provider organizations consolidate. In general practices almost never just shut down; some other provider organization takes them over and assumes responsibility for the records. The remaining small medical offices don't have the IT capacity to implement sophisticated new data sharing mechanisms anyway.

Giving patients copies of their records — while a good practice in general — doesn't solve this problem. Patients lose their records, forget their passwords, don't understand how to use the systems, etc. That's why most medical records will continue to be shared on a provider to provider or payer (insurer) to provider basis.

> blockchain is useful outside the context of cryptocurrencies because it represents a verifiable chain of custody.

That's like saying "rockets are useful because they allow to go to other galaxies faster". True enough, but going to other planets involved some technical details which current rockets do not exactly solve.

So, blockchain does represent verifyable chain of custody. But why this chain of custody is good for storing my health records (especially given that it's public)? How it can be guaranteed that there always be miners ready to carry my health info around? Who will be paying those miners and why it would be cheaper and more convenient than storing the info at regular data store? Right now miners' investments are essentially paid by hype that cryptocoins always raise. Once that stops - and it has to stop - who'll be paying it?

> Now imagine what happens if your doctor dies

It looks like you are arguing for personal data portability, but what this has to do with blockchain and it's properties? Why blockchain specifically is better here? Why not just requiring my health provider to allow me to access and regularly backup all health data they have?

> And something that blockchain could fix better than just having some federally regulated centralized medical record repository

I haven't seen any indication why it's true, could you explain why it is the case? I do not consider situation like "US federal government collapses", because in this case there would be no internet, no electricity, no working major hospitals and having up-to-date information would be not super-important because I'd be too busy trying to stay alive and fend off looters trying to steal my canned food reserve. In the normal everyday situation where we have functioning (as well or poorly as it is now) federal and local governments, why is it better?

> Blockchain allows you to maintain personal and private control of your records,

How? As far as I understand, once something is integrated into the blockchain, it is unmodifyable and accessible to all (well, maybe in encrypted form but still, keys can be stolen too) - how can I control it? Bitcoin theft proved that you can't really control your coins if somebody gets to your keys, and you can not reverse transactions once they are approved - actually, that's one of the design features. So how would I exercise such control exactly?

An append only logfile is easier, more reliable and more interoperable

Just require that each change is digitally signed with the doctor's key

doesn't seem that you have done a lot of research on the subject really.

You are wrong, I did a lot of research, but you obviously did so much more that it would be easy for you to answer my questions. Hopefully, one day your busy schedule would allow you to do it. It is a pity for now it only allowed to post a content-free comment.

should get you thinking why there is so much hate for blockchain and at least be a contrarian here. What can I tell you? Read books about Bitcoin and Ethereum? The "how blockchain will help people" is a huge subject. Did you spend hours/days/months thinking about how this can affect governments, global title deeds, transparent balance sheets, supply chains and well...voting too? If you think you ever in your life had to deal with corruption or simple mistakes then you can think of a blockchain solution. Is that what you wanted to hear? Asking about "how the internet will affect our lives" in 1995 would be the same, but it would be better first to read about what exactly it is. So you went to this OSCON..

> should get you thinking why there is so much hate for blockchain

Where "there"? I haven't seen hate anywhere.

> Read books about Bitcoin and Ethereum?

I know what Bitcoin and Ethereum are. What I don't know is what they are useful for in the real world (except, obviously, speculating on Bitcoin or ETH prices. Well, I guess buying/selling drugs with them online must be pretty good too, and malware authors love it... what else?). If you know books that cover that, you are welcome to suggest.

> The "how blockchain will help people" is a huge subject

I do not ask you to cover 100%. I ask you (and anybody else, of course) to start with 0.01% and then we can proceed from there. But you're not giving me even 0.01% - you tell me "read books, it's huge!".

> Did you spend hours/days/months thinking about how this can affect governments,

I must admit I didn't spend months thinking about it. But people who claim they know answers to these questions surely did, didn't they? So where are those answers? I want to hear them. I want to see a good substantial proof why blockchain voting is better than plain old voting and how it is sustainable on the scale of a country like the US, in the long run.

> If you think you ever in your life had to deal with corruption or simple mistakes then you can think of a blockchain solution.

This is a point I know somebody tries to sell me a nice vial of snake oil. Corruption is human nature, and if you think some cleverly arranged crypto is going to fix it, you have some surprises coming your way. But ok, maybe I'm just stupid and cynical and you're smart - tell me how blockchain fixes corruption. Don't give 1000 examples - give three best ones you can think of.

> Asking about "how the internet will affect our lives" in 1995 would be the same

If you asked me how internet will affect our lives in 1995, I could talk to you for days with specific examples. Surely, some of them would be wrong, and some of what happened I couldn't predict in my wildest dreams. But by then it was clear there's a big thing coming, even if not as big as "old economy does not apply anymore". I don't see why a series of hashes plus a good marketing strategy allowing to sell those hashes to people who hope to resell them to the next greater fool equals big thing. Maybe it's because I'm stupid - in this case, it'd be easy to show me some conclusive examples. So far I've see a lot of vague handwaving and very little specifics. Which makes me even more suspicious.

Reply on news.ycombinator.com