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Comment by Moodles | Hacker News Reader

I have a PhD in cryptography. Please be precise. Exactly what problem will blockchain solve for vehicles? You can't just hand wave and say stuff like "decentralized trust management" and expect us to nod along.

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Yeah, I'm quite skeptical of it as well. If I'm being really charitable to it, then it's a way to synchronize data between parties without relying on a trusted intermediary. That said, it's unclear what practical value that has outside of purely digital applications like cryptocurrency. When you roll it into things in the real world (e.g., supply chains, health records, etc.) then you necessarily have to trust the data sources and sensors, at which point what good is a blockchain?

Which is exactly the point I still try to get my head around when it comes to supply chains.

First, for blockchain to work you need trustable sources. Problem is, when the aource is trustworthy, what added benefit comes from a blockchain?

Second, having a, theoretically uninterrupted blockchain from the first raw material to, say, a car would provide way to much insight into supply chains. I pretty sure companies do not want that.

Finally, and that is IMHO the haedest point to practically solve, you need to make 100 percent sure that the physical and information flow in your supply chain are never ever seperated. One single separation and your whole blockchain is worthless. And that risk is so incredibly high in the real world it's almost laughable. So, to make sure a given blockchain matches the physical product you need a trustworthy party to assure that. And then, what value does blockchain add?

Someday someone a lot smarter than me will find a use case. At which I will say how damn obvious it is.

It's not an end-all for supply chains, but that doesn't make it useless. It still prevents forgery of old records. If someone signs something, they can't later go back and change it or claim they didn't.

Have you worked in manufacturing with ERP systems and BoM transactions?

I could see how this would be useful for medical device manufacturing, especially something like a pacemaker.

Indeed I did. Thing is, I see how blockchain could help existing processes. I just don't see the revolution yet. Which puzzles me, since on the one side I see the potential but on the other hand I still fail to see a real use case. And that introgues me quite a lot.

Indeed I have conjectured multiple times that I think the only application of blockchains is in cryptocurrency. Introducing any physical asset like a yacht or a banana in Laos or a diamond in Africa really doesn't make sense: you can't literally put those physical things in the blockchain.

> you can't literally put those physical things in the blockchain

You can not otherwise too, right? A blockchain holds interactions/transactions not the data itself. Most blockchains are incredibly small in size. For example, the size of the entire Bitcoin blockchain is 215.84 GB [0].

[0] https://bitinfocharts.com

I can see its applicability in any kind of chain of trust for distribution of physical goods that have a potential to be counterfit or improperly handled/processed.

Also, I see a possibility for licensing/DRM of some types of media IP.

That does not mean it needs to be distributed, though.

I agree. You would need an oracle in order to put physical things on the blockchain, and that is subject to incorrect data or tampering. It's non-trivial, but not technically impossible.

Yes, but if you have a mechanism (either technical or institutional) that you trust to attach real-world goods to your blockchain in a sufficiently correct and tamper-resistant manner, why not just let that mechanism manage your ledger directly and skip the blockchain entirely?

Those seem like two separate problems to me. The oracle reliably reports to the blockchain while the blockchain ensures that the historical record is tamper-proof.

But why can you trust the oracle to report correctly but not to maintain the record?

> it's a way to synchronize data between parties without relying on a trusted intermediary

At the expense of time. So most real-world use cases (securities trading, vehicular networks, payments) fail when you introduce a 10-minute delay required for distributed confirmation.

For time-insensitive examples you've provided - supply chain and health records - the use cases work better, but who will dedicate the resources and mine the blocks to ensure that specific blockchain's survival?

Say you initiate a contract to sell a yacht for 1 million $. You and your buyer go to a notary where all 3 of you sign the contract and all the proper procedures. You give the buyer the yacht and he says he will transfer you the money tomorrow. Meanwhile the buyer and the notary strike a shady deal to screw you over and make new contracts that say you sold it for 1k$. It's 2 against 1 and you will lose a costly court battle and your yacht and so on.

Solution: blockchain smart contracts where code is law, more secure, trustworthy and transparent than any individual, bank, government or company.

But code isn't law. You would have to rewrite parts of the legal system to support blockchain tokens as representing actual ownership, and there's strong reasons why you would never want to, such as loss of private keys, forgetting of passwords, or security vulnerabilities, or user error leading to complete asset loss.

Otherwise you have a synchronization problem between the upcoming blockchain token system and the existing government deed registry, and of course the government registry would take preference, and has a history of working just fine for lower cost.

This video is an excellent overview of this topic: https://www.youtube.com/watch?v=YxmXIgLEAIE

I haven't seen blockchain systems as being more secure or more trustworthy. I see them being overhyped, subject to lax and magical thinking, and full of theft of coins due to hacks and scams.

"and has a history of working just fine for lower cost." Citation needed.

Also we are just talking opinions here, a lot of things seem impossible until they are actually here and in our everyday lives.

Maybe you should try watching the video I already cited, specifically this part: https://youtu.be/YxmXIgLEAIE?t=1404

You might learn something.

You are trying to solve a problem with a blockchain that does not exist. Also, exactly how does your blockchain even know "this yacht now belongs to this person"?

Exactly. How does the real world's state get accurately put into a blockchain? My big beef with all the blockchain hype is that this doesn't seem to be addressed. They say "trustless" and "secure" and "transparent" all the time, but those assurances only exist within the very limited confines of the data structure itself. As soon as you hook it into real-world data, then those assurances only guarantee that fraud is accurately carried out.

It doesn't. You go to court like normal people.

How is this not a problem if the court system is filled to the brim with situation that could have been solved with smart contracts in place.

As for the yacht it's easy, the ownership is transfered from your address to the buyers address on the government's blockchain. :)

hey everyone lets record every transaction from everyone on a big government database so we can solve trade disputes if someone steals my yacht and crashes it.

Let's say I'm the buyer and this happens. There's now a record on the government blockchain that says I own a yacht. Does that mean I physically have possession of the yacht now? How do we assure that what's in the blockchain is an accurate reflection of who actually has physical possession of the boat?

> blockchain smart contracts where code is law, more secure, trustworthy and transparent than any individual, bank, government or company.

The DAO issue [0] clearly showed that "code is law" doesn't really work. It's people writing cryptocurrency software and running the nodes that are "the law".

[0]: https://www.coindesk.com/ethereum-executes-blockchain-hard-f...

If you and the buyer already have physical contact, you don't need a trustless system, you take him to court or vice versa if one party is unhappy with the transaction.

The blockchain can't (or at the very least shouldn't) overwrite legal infrastructure.

But you still lose your yacht because it's not in the blockchain.

Is it just me or do the replies I'm seeing come across condescending and unsubstantial? I'm also missing why your PhD in cryptography is any important for the sake of the argument. We are not you in regards to your last remark by the way: "...expect us to nod along". But since you are looking for a good argument to support your confirmation bias, blockchain itself doesn't solve anything. It's just a data structure and a tool. The problem solving happens in the bigger picture, e.g. "decentralised trust management".

But let me ask you this: exactly what problem will a database/tree/file solve for vehicles or currencies? We can agree upon that what you are asking and looking for can't be answered or will get a reply similar to: we don't have that problem. You may have asked the wrong question though.

Let me be more precise and create a problem that doesn't exist but for programming purposes I want these requirements: many users should be able to read a (hardly) modifiable data structure that gets more resilient the more use it and that is a singleton who everybody has access to (call it decentralised if you will). Blockchain sounds like a perfect fit doesn't it? Now, when we replace the data structure keyword with OS and resiliency with speed, we can agree upon that this sounds like a decentralised operating system (Ethereum or whatnot).

Don't get me wrong. I don't see any problems that need to be solved with blockchain right now either. But clearly there is a trend in cryptocurrencies and decentralisation that seems to be important to a lot of people. There are tons of problems that need solving: trust misuse, censorships, privacy issues, advertising and so on. That there is a need for a change is obvious. That this change started with blockchain technology is good. I'm also sure cryptography is important to you too. Why not embrace an emerging technology that benefit your field of study?

This is the example I was referring to: https://ieeexplore.ieee.org/document/8358773. The problem is one where there are multiple vehicles, from different manufacturers, that must communicate with each other in real time (say at an intersection) and must make decisions based on messages being relayed to them. This is easier if they are all following the same protocol.

There is no need to have a database replicated everywhere across a network and for all nodes in the network to be constantly engaging in a consensus protocol to agree upon the state on the ledger for some cars to communicate.

Almost always a blockchain is (i) useless or (ii) something kinda vaguely like Satoshi's blockchain but really more like Git.

There is an important qualifier that people keep forgetting.

You wouldn't need such a system for cars to communicate in the presence of authority or in the absence of value. The former is the case for Lyft or Uber, the latter is the case if we have an infinite supply of cars.

But if one wishes to have peer-to-peer value (and cars ain't cheap) without a central authority (and Uber is evil) a proof-of-work blockchain is better for that than Git or a server run by some guy is.

There may of course be superior social or technical forms for this use case. But once you have added the qualifier that the system should be decentralised (and for everyone making a career out of pretending not to understand what this word means: I mean here that there should be no central point of control at the point of transaction) a blockchain may make more sense than some of the alternatives.

I agree for this particular case, which is why I think a DAG with local consensus (something like IOTA) is more applicable for this application.

I think DAGs are possibly even more useless.

And you're of course free to have your own opinion. I'm not as quick to dismiss them simply because I acknowledge that new technologies have historically been ridiculed by experts at least initially. But healthy skepticism is always warranted.

And of course the best protocol for a real time, latency sensitive application is... using a blockchain?

Bitcoin has a throughput of about 3 tx per second. Ethereum a little better at 7 tx per second. Confirmations are on the order of minutes at best.

Why do you think this would be a good idea?

Those are blockchains which come to global consensus, which I don't think would work here. You would either need a state channel (2nd layer) or a DAG structure.

Service records for the life of the car.

Vehicle purchasing/financing paperwork.

Inspection tracking.

Trust and transparency.

Are you capable of being precise?

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