For a detailed description see this: https://grisha.org/blog/2018/01/23/explaining-proof-of-work/
I agree with you, I always thought that the Bitcoin algorithm was very clever and "mind opening" in a way. It's one of these things I'd never have thought about but almost seems obvious in hindsight. What's even more interesting is that basically all of it is pre-existing technology: HashCash, ECC, Merkle trees etc... Just combined together in a clever way to create something that's more than the sum of their parts.
Now where I become a naysayer is when we switch from the realm of intellectual curiosity and into the world of cryptocurrencies today. Being clever and innovative doesn't necessarily mean useful or valuable. We have plenty of clever ideas out there that don't have much of a practical use (or used to have one but are now obsolete). Duff's Device, sleep sort, the fast inverse square root, one instruction set computers, code golf and 4KB demos ...
I think I do understand the technological value of Bitcoin's PoW blockchain, I just think that its only practical use is for a tiny niche. It's the Prolog of consensus algorithms, I'm sure it'll be useful to some but I doubt it's going to be the new C++. You say that "It uses proof-of-work to establish consensus over points in time which are universally unique" and it's true but how useful or valuable is that? Is it such a huge problem in our modern society to agree on a sequence of events? Do you often program something and think "man, I wish that there was a way to establish a consensus over points in time which are universally unique" and 1/ there's no other simpler solution to achieve that and 2/ a blockchain could actually solve it? There's only a tiny gap between these two propositions.
But I think at this point talk is cheap and all that needs to be said about the blockchain has been said long ago and multiple times. How many billion of dollars has been poured into "blockchain" technology these past few years, in the form of pre-mined coins or ICOs? How many hundreds of engineers are working on those killer blockchain applications? How many high profile companies have boldly announced blockchain-related tech investments lately? So.... where are the results? How long do we wait for them until we decide that maybe it's not that revolutionary?
No, not really. The way proof-of-work is used is nothing like in HashCash (more generally known as a time lock puzzle), the solution to a decentralized clock is the one piece that is new. In the paper it is referred to as "Timestamp Server". Everything else is previously known tech, but the clock piece is an invention, the invention that made it all possible.
I'm not trying to diminish the discovery, it's quite the contrary, I think its simplicity and elegance is what makes it so impressive. It's a very elegant solution to a very complex problem and you could explain it in a few minute to somebody with the right technical background.
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That class of actor can even potentially avoid the financial sunk costs that would ordinarily be required, although that in turn would require the use of several zero-day exploits and/or the use of similarly high-value resources usually available only to state-level actors.
Still, under certain circumstances I could see something along these lines being the opening move in World War IV (not to be overly dramatic or anything). Or perhaps a much smaller conflict, should any state be foolish enough to standardize on a national cryptocurrency of their own creation for internal use.
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Medical Records
Mid aughts, I was trying to figure out how to use tamper evident logs (rolling hashes) for our electronic medical records infrastructure. To answer questions like "what did you know and when did you know it?" and "where did this bad data come from?"
Coupled with the notions for Translucent Databases (all data at rest is encrypted) to protect privacy.
We hadn't even gotten to the consensus and trust issues.
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Authenticity
I'm now most interested in verification of sources.
Where did this cotton or wheat or cobalt come from? Are these pills authentic?
Is the data cited by this paper legit?
Verify copyrights, perhaps even a realization of Ted Nelson Xanadu's notions of transcopyrights. (Disney's DragonChain and others have floated those use cases.)
Is this news report real or agitprop? Is this quote actually legit?
Did someone(s) silently update some published information?
Etc, etc.
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Tursted Rules & Constraints Satisfaction
Since seeing a presentation on using ethereum style smart contracts for medical claims processing, I've been reading up.
I can barely wrap my head around this stuff. Computability, Turing complete, N vs NP, etc. But the domain experts I heard told a great narrative, so now I'm interested too.
And even if you manage to solve that problem, the blockchain still doesn't help with medical records, authenticity or anything else. You still have to trust the people entering those records. you still have to trust that the person who said "those pills are authentic" on the blockchain.
Smart contracts are also the biggest pile of hype. You can't have "code is law" because other wise you wind up with The DAO.... All code has bugs. All code has corner cases where assumptions fall apart. You can't code law.
Blockchain is pure, 100% hype. Almost every single use case falls apart under even a small amount of scrutiny. The only use the blockchain serves is as a platform for fraud. If you are a scammer, there is no better place to be than in crypto.
It's turtles all the way down, right?
None of my proposed use cases rely on PoW, bitcoin.
Perhaps I should have said it more clearly: I'm not interested in currency et al, because best as I can tell, bitcoin is just a better escrow, or worse a collectable (like baseball cards). And those things don't interest me.
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Have you done accounting, bookkeeping, auditing? Another way to think about blockchains is an interoperable ledger. If your data doesn't leave your org, you can just using tamper evident logs (rolling hashes), no consensus stuff required.
I worked on election integrity issues for a decade. I'm the biggest technoskeptic. I pretty much oppose all things new until they're battle proven.
The biggest challenge for election administration is verifying and publishing the physical chain of custody of all the gear and materials. And no matter how hard you try, there's always some yahoos (flat earther types) that will demand ever greater proof.
Whaddya gonna do?
Well, based on my experience, applying some blockchain technologies to document and publish chain of custody would simplify A LOT of the public accountability and transparency issues.
At the end of the day, it's just double ledger accounting. Debits match credits. The parts of blockchain that interest me make it easier to "show your work".
https://www.cis.upenn.edu/~ahae/papers/peerreview-tr2.pdf
https://eprint.iacr.org/2005/002.pdf
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.625...
And here's you a blockchain-based solution to medical sharing since you said you were looking into such things.
Those papers are from about the same time frame, but I don't immediately recognize them. I do remember the implementation I modeled mine after was patent encumbered.
I may have adopted "tamper evident logging" because I was talking to a lot of non-geeks at the time and they were familiar with terms like "tamper evident seals".
That MeDShare paper is kinda weird. We were very fortunate to have domain experts (nurses, doctors, admins) on staff. So what we ended up with (after a few years) didn't look much like what MeDShare proposes. For example, access control is a non-starter, because in an emergency no one cares about permission. So the best we could do is log access. Also, demographic data at rest is plaintext, because in the USA there's no GUID, so you need access to all the fields to do record matching (linking) and mitigate poor data quality.
Repeating myself: my interest in tamper evident logging was for legal liability and improving our own QA/test.
I haven't thought much about all the other areas blockchains could be used in medicine, like prescriptions.
But if there's some meat on those bones, I wanna know about it. I think of it as a constraints satisfaction problem. If the "vocabulary" can be kept simple enough, where our current theorem provers are sufficient, that could be cool.
Did we really?
BTC vs BCH, Ethereum vs Ethereum Classic. Sigwitx2.
These hardforks technically break established consensus and rely upon social means (hey everyone: switch algorithms right now!!) to stay in order. At the end of the day, it seems to me that the "blockchain" is only as strong as the community's resolve to work together.
As far as I can tell, Bitcoin is turning into a governance structure. The current power players are the devs, who most people trust (and I see no reason not to trust them). And the social structure is organized on Github and forums.
As do clubs, corporations, and "Roberts Rules". People have been making secret societies and private laws since the mid 1850s. That's a long solved problem. Chuck-E-Cheese tokens, Disney Resort Meal Points, and hell, even credit card money is "made up money" to some extent.
For example of all the above: https://en.wikipedia.org/wiki/Capitol_Hill_Babysitting_Co-op
The thing is, people need to understand the laws for them to be useful. You can't just "outsource" the rules to the blockchain.
My point is that the currently established social structure behind these cryptocommunities is horribly defined right now. Its pretty much structured around trusting a few developers. The key for success is a true governance body. Blockchain doesn't solve the hard problem at all. (Case in point: should Ethereum hardfork right now, or wait for Proof of Stake? GPU miners want a hardfork ASAP due to the ASIC miners incomming, but the rest of the community doesn't want unnecessary hardforks. Finally, the ASIC-investors definitely don't want a hard fork.)
Someone needs to make a decision, and a group of people will lose out. Probably the ASIC guys / Bitmain based on the current political environment.
But then it all begs the question: if everyone is centralizing trust in the developers, then what the hell is the point of the blockchain? Its no different than trusting the rules of the Capitol Hill Babysitting Co-op and their fake monopoly money (erm... babysitting "scrip")
The New Oxford American Dictionary defines technology as "the application of scientific knowledge for practical purposes". If the application does not fulfill the purpose, the technology is crappy, regardless of how brilliant the science behind it is. The author is not saying that the science is crappy but that the technology -- i.e. the application for the practical purpose -- is.
http://satoshi.nakamotoinstitute.org/emails/cryptography/11/
The magical thing is that you can actually know that the distributed system is consistent by how much work was performed.
what was the problem that this solved, exactly?
But the myth that people create amazing technology that has no use (TCP/IP, the computer), and then a decade later people discover what it's useful for, is just that: a myth.
It is even in the name. The "Internet" was not some monolithic project. It was a way of connecting the many different networks that had already been built.
> A winner of the Nobel Prize in Economics, Paul Krugman wrote in 1998, “The growth of the Internet will slow drastically, as the flaw in ‘Metcalfe’s law’—which states that the number of potential connections in a network is proportional to the square of the number of participants—becomes apparent: most people have nothing to say to each other! By 2005 or so, it will become clear that the Internet’s impact on the economy has been no greater than the fax machine’s.”
My prescriptions are the real deal.
As a better escrow for exchanging goods, services.
I can verify if the trog on Fox News is just making shit up. (Verified sources, citations are baked into all content.)
> My prescriptions are the real deal.
How does the blockchain solve any of this? You still need a human to say "this Gucci handbag is not counterfeit". A human still needs to type in "yup, this prescription is real".
Accounting.
For this use case, think of blockchains as a shared ledger.
A blockchain-based shared ledger is only useful in case the participants don't trust each other. In which case you cannot do anything with it to help detecting counterfeits.
The original articles goes into this very problem. What's to stop your mango provider from spraying pesticides all over their mangoes and then entering "organic" into the ledger?
I'm not saying blockchains are a cure all. I'm saying I'm keenly interested in using shared ledgers for this use case.
My experiences with election integrity, for better or worse, inform my views (optimism). There was a lot of interest in auditing elections. And it was studied extensively.
For my part, I read up on Medicare fraud and forensic accounting, because they seemed to be the most mature related domains (at the time). My conclusion was that reducing fraud is best accomplished thru simplifying the accounting.
You still need relationships and face-to-face and "trust but verify".
My ultimate hope is that something like blockchains (not talking cryptocurrency, bitcoin, PoW) will somehow make the chasm between the physical and digital worlds smaller. Thereby reducing transaction costs, waste, fraud, uncertainty and so forth.