I hate the blockchain hype. I think most uses can be solved by a simple database hosted by a trusted authority. Yet, just reading the first two samples, I already disagree with them.
Re the 1st one: it's true only if the transporter doesn't risk anything if the sensor is tampered with. As soon as you introduce strong fines and/or consequences if a validating authority randomly checks your goods and discover some tampering, the system is a bit more likely to be trusted. But of course, in such a case, you might as well just host the temperature log with the validating authority (like it's done for Concrete, or in the Auto industry).
The second one is even more compelling: of course the trust chain stops when the trust chains stops ! But if every luxury Louis Vuitton handbag is tracked and you know precisely whether it's been sold or whether it's supposed to be sitting on a shop shelf somewhere, you have zero risk of double sell (or at least, within the same limits as a bitcoin double-spend).
In the second case, couldn't Louis Vuitton also host the associated records itself?
There are several concepts related to this in other areas: provenance, catalogues raisonnés, serial numbers, title registries, pedigree registries, among others. People who make or who deal in rare or expensive things often adopt some of these mechanisms to help answer questions like: which one is this? is it genuine? who owns it? who used to own it? is it stolen?
(There are lots of different threats, but some of these mechanisms help respond to each. Properly identifying and authenticating an individual object may be the hardest problem of all here—but that's potentially less of a database issue than the others.)
Unsurprisingly, catalogues raisonnes are a hotbed of legal activity and controversy. Many scholars will now not offer opinions on the authenticity of a work for fear of getting sued:
Due to the misaligned incentives in the art authentication world, I'm going to go out on a limb and suggest that a blockchain would be a good way of tracking records in the artworld, particularly if artists register works directly on it.
By putting your artwork on the "BitCoin Blockchain",
Verisart will hand wavy magic increase the trust in
art dealers and reduce fraud.
That's a pretty neat idea. A distributed public ledger of
who I have sold my art to. And, if they sell it, they have
a cryptographically signed certificate proving its
provenance. The seller can sign the certificate with their
private key to say they've sold it to the new owner of a
specific public key. Nifty!
Except… and I hate to bring the art industry into
disrepute… what if I sell a fake and keep the original in
my Underground Vault?
There's no way to permanently attach a digital certificate
to a physical work of art.
Incidentally, this is the problem with all the startups
claiming the blockchain will revolutionise the integrity
of global logistics markets. Sure, you can slap a QR code
on a crate - but nothing stops an unscrupulous middle-man
from replacing or adulterating the contents of the crate.
Let's get back to Verisart's other issue. Proving that I
am the creator or owner of a piece of artwork.
Long story short, I convinced them that I painted the Mona
Lisa.
In China there is a lot of issue with fake milk powder. You can now buy powder which contains a barcode in the container sealed at the factory that you can look up online to Ensure it came from the factory and not a 3rd party counterfeit. Blockchain adds exactly 0 value to this.
> What if the trusted authority is the Chinese government? would you still keep your same opinion?
It's not about how nice the trusted authority is. It's about the value the trusted authority provides.
If you're doing business in China, although you might not entirely trust the Chinese government, and might not like them, they'll still provide more value than a "trust-less" system. China is not a lawless state after all, and if you want to do business there you'll have to deal with them at some level.
> At the core of it, it is a transfer of power from larger organisations to the people.
It's not though, if there's no actual transfer of real power. It's naive to think that blockchain themselves do this. If people tried to circumvent the Chinese state with blockchains in any meaningful way, China would crack down on it, and they'd be very efficient at it. Because real power is about interfacing with the world in real ways, and a well-functioning state will always maintain that power.
It's possible that, through democracy or other forms of pressure, people could make the government and businesses accept, use or interface with blockchain technology. But if people do have that kind of power over these entities, people by definition have the kind of power that makes the value of blockchain tech vanishingly small.
Blockchains provide value - not when you don't have any party you trust fully - but when you don't have parties that can provide any kind of value through their trust. I.e. failed states and lawless territories basically.
> It's not though, if there's no actual transfer of real power.
Blockchains are hard to modify and as such, can act as a form of checks and balances against those trying to change history. You're kind of saying powerful entity won't allow checks and balances and somehow conclude they are unnecessary. That is ... unfounded.
>As soon as you introduce strong fines and/or consequences
If strong fines were sufficient to prevent tampering then the proposed blockchain solution wouldn't even be necessary; just fine dishonest actors, period.
> if every luxury Louis Vuitton handbag is tracked and you know precisely whether it's been sold
There is no way to accomplish this though. You cannot reliably track a physical object because there is no way that a computer can automatically verify the authenticity of an object.
> I think most uses can be solved by a simple database hosted by a trusted authority
People say this in every blockchain related thing that pops up on HN but it excludes literally the only legitimate use case for a blockchain. That being the scenario where you don't have or don't want to rely on a trusted authority.
This seems clearly true for applications related to censorship resistance and certain properties of money and financial systems (if you explicitly don't want a government to make certain decisions in the systems), but maybe not for many other applications.
For example, is it likely that people don't trust Louis Vuitton to decide whether Louis Vuitton handbags are genuine? Isn't that the definition of a Louis Vuitton handbag being genuine?
In most cases where an institution is empowered to make a decision of some sort, the risk that they will later change their mind arbitrarily doesn't seem to loom very large. (I'd agree that it's great to have mechanisms for detecting this, although regular digital signatures and Merkle trees may suffice.)
People say this because blockchains are currently extremely complex and expensive in exchange for the value prop "don't need to be hosted by a trusted authority". That doesn't mean the value prop doesn't exist - it just means there are better tradeoffs today.
There are tons of cases where groups of entities interact and don't inherently trust each other. That is basically all of trade. In all of these cases, it would be more ideal if no one party had to be a trusted authority.
As soon as it seems simpler and less expensive for blockchains to implement this behavior, they will suddenly become a useful tool for all kinds of applications.
I think _you_ are missing the point. Bitcoin resolves the problem where funds from wallet X are moved into wallet Y. That alone does not solve much. I still have to trust that whatever I paid for will be delivered. And worse, if it isn't I have no way of reversing that transaction.
The moment I go to an authority and file a complaint, I am trusting that authority. I might as well just use their fiat as well.
The point above is that if I cannot trust the authorities (because my transaction is illegal), then there is a use case for bitcoin.
> That being the scenario where you don't have or don't want to rely on a trusted authority.
This doesn't even remotely solve the problem.
If someone can get a 51% attack, you now have a trusted authority. If you have a cabal of developers who are implementing your blockchain (and who the overwhelming majority of users will follow if they decide to fork), you have a trusted authority.
In the case of supply chain management, you need a trusted central authority regardless. Who ensures the sensors are honest? A computer can't do that. It has to be a legal contract between the truck company and a central authority, backed up by the dreaded guys with guns.
Re the 1st one: it's true only if the transporter doesn't risk anything if the sensor is tampered with. As soon as you introduce strong fines and/or consequences if a validating authority randomly checks your goods and discover some tampering, the system is a bit more likely to be trusted. But of course, in such a case, you might as well just host the temperature log with the validating authority (like it's done for Concrete, or in the Auto industry).
The second one is even more compelling: of course the trust chain stops when the trust chains stops ! But if every luxury Louis Vuitton handbag is tracked and you know precisely whether it's been sold or whether it's supposed to be sitting on a shop shelf somewhere, you have zero risk of double sell (or at least, within the same limits as a bitcoin double-spend).