How Blockchain Works • Hacker News Board

Re: How Blockchain Works

#81

Post by neospice » Wed, Sep 26, 2018, 4:17 PM UTC

vec wrote: post #79

gibsons77 wrote: post #17

Earlier quoted context omitted.

Well.. It will change some aspects of our world. Particularly financial assets at first, but increasingly it will play a role in any peer to peer exchange requiring trust. Simple past examples are systems like OpenPGP that bind public keys to owners. Programmable blockchains allow generalized applications requiring decentralized trust. A good example of a use of blockchain outside of financial assets is in trust mana…

> Programmable blockchains allow generalized applications requiring decentralized trust. Yeah, they don't really though. They allow a few extremely specific applications requiring decentralized trust. The trust guarantees only hold if no single party can, even momentarily, control more hashing power than was collectively used to generate the last X blocks, where X is number of updates made since the data you want to…

Please forgive my ignorance if I’m missing something obvious but in your PGP public key tampering example, wouldn’t this attack be ineffective against a blockchain that is stored in multiple peers. I.E your hashes wouldn’t match those of the peer copies of the blockchain?

Re: How Blockchain Works

#82

Post by yarrel » Wed, Sep 26, 2018, 4:19 PM UTC

Moodles wrote: post #39

gibsons77 wrote: post #34

Earlier quoted context omitted.

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.

Re: How Blockchain Works

#83

Post by poulsbohemian » Wed, Sep 26, 2018, 4:20 PM UTC

thedancollins wrote: post #33

Over the past year I have gone from Blockchain enthusiast to more blockchain gadfly. The concept is truly revolutionary but the use cases I typically see trotted out are not compelling in any significant sense and could be solved without blockchain. I believe the reason for this is due to the fact that the true value of a blockchain solution is not in the data aspect of it (which everyone gravitates to and can quickl…

Can you give an example of this transactability, especially in an example where it would be superior to existing solutions?

Also, are you the Dan Collins in Phoenix? I think we did a project together about 4 years ago...

Re: How Blockchain Works

#84

Post by neospice » Wed, Sep 26, 2018, 4:21 PM UTC

vec wrote: post #63

gibsons77 wrote: post #48

Earlier quoted context omitted.

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.

Re: How Blockchain Works

#85

Post by cryptica » Wed, Sep 26, 2018, 4:23 PM UTC

I remember that a lot of people were saying that cryptocurrency is not revolutionary but that blockchain is. I think the opposite is true. Cryptocurrency is revolutionary and blockchain is just one of several known technologies that make it possible. Cryptocurrency is the most important use case for blockchain tech.

What I like most about cryptocurrency is the fact that it financially incentivizes massive collaborative behaviour without requiring participants to actually own any capital at the beginning. It lets you create financial incentives out of nothing. Before cryptocurrency, this kind of collaborative game-rigging behaviour was only accessible to people who owned a lot of capital (e.g. 'activist' investors).

For example, I could launch my own cryptocurrency tomorrow and then use it to air-drop (aka bribe) journalists to write about my project in a positive way - This is pretty standard behaviour among Silicon Valley startups but now you can do it without VC money.

It sounds bad but it's much better than what we have now.

It levels the playing field for everyone. For the first time ever, regular people have the power to change the world together through incentivised collaboration.

Re: How Blockchain Works

#86

Post by Razengan » Wed, Sep 26, 2018, 4:27 PM UTC

I have yet to watch/read the link, or catch up on the hype, but why is "Blockchain" referred to in the singular? As in "the blockchain" or just "blockchain" (often capitalized.)

Is there only one of its kind?

Is "How Internet Works" grammatically correct?

EDIT: I didn't see this was already asked in another comment.

Re: How Blockchain Works

#87

Post by vec » Wed, Sep 26, 2018, 4:28 PM UTC

neospice wrote: post #81

vec wrote: post #79

Earlier quoted context omitted.

> Programmable blockchains allow generalized applications requiring decentralized trust. Yeah, they don't really though. They allow a few extremely specific applications requiring decentralized trust. The trust guarantees only hold if no single party can, even momentarily, control more hashing power than was collectively used to generate the last X blocks, where X is number of updates made since the data you want to…

Please forgive my ignorance if I’m missing something obvious but in your PGP public key tampering example, wouldn’t this attack be ineffective against a blockchain that is stored in multiple peers. I.E your hashes wouldn’t match those of the peer copies of the blockchain?

Nope. The whole point of proof of work is that it informs clients which version to consider authoritative in the case of a conflict. If my tampered copy has higher proof of work than the peer with the correct version then, by definition, mine is correct and the other peer's is outdated. Correctly implemented peers will recognize this and overwrite their local cache with mine, and even if they don't other peers will always prefer my version to theirs when deciding which update to sync.

Re: How Blockchain Works

#88

Post by yarrel » Wed, Sep 26, 2018, 4:32 PM UTC

Moodles wrote: post #45

easymodex wrote: post #16

Earlier quoted context omitted.

Well it has great potential to remove a lot of beaurocracy related stuff. It's not really the next internet but it can very easily change the world if it's properly implemented. But if you're talking specifically about cryptocurrencies and bitcoin then I assume you're a bit salty because you think you missed the hype. Don't worry tho, we are still early adopters.

I actually conjecture that blockchains are only useful for cryptocurrencies like bitcoin. It's when you see companies using them for tracking their supply chain, their music, their photos, their porn, their bananas in Laos, their weed, that I roll my eyes into the back of my skull. There's no way it has any potential to simplify any beaurcracy, unless you think introducing multiple nodes on a network and constantly m…

Trust.

If you are a small producer and you send a shipment of your widgets to Wal Mart, and Wal Mart then say "what widgets?", the efficiency of their SQL Server installation isn't a benefit that will bring you much comfort.

If you are a small producer and you send a shipment of your widgets to Wal Mart with little rfid stickers on tracked by a blockchain system that you, the shipping company, border security, Wal Mart's warehouse and Wal Mart's stores run nodes for, you have a system that may bring you a bit more comfort. Running a node is simpler (or at least more efficient - pen and paper is simpler than SQL Server...), and the outcomes more encouraging for all participants, than some of the alternatives.

The question "Why not just banks using computers?" is where distributed timestamp servers came in and there is an extensive literature devoted to both the ideological and practical arguments around this. Briefly because banks are untrustworthy, expensive and slow. Banks themselves using blockchains is recuperation ideologically speaking, and FOMO technologically speaking. It is less silly to the degree that it does improve banking transparency and trustworthiness, but abandoning proof-of-of-work for the nonsense of "permissioned" blockchains restores it to being very silly.

Re: How Blockchain Works

#89

Post by w1nt3rmu4e » Wed, Sep 26, 2018, 4:34 PM UTC

thedancollins wrote: post #33

Over the past year I have gone from Blockchain enthusiast to more blockchain gadfly. The concept is truly revolutionary but the use cases I typically see trotted out are not compelling in any significant sense and could be solved without blockchain. I believe the reason for this is due to the fact that the true value of a blockchain solution is not in the data aspect of it (which everyone gravitates to and can quickl…

Honestly, I don't see why everyone hates blockchain these days. Two things are going on:

1. It's a potentially revolutionary technology (trust-less, decentralized, nearly tamper proof, etc) that hasn't yet found a killer app(s) at scale

2. We're in the middle of a gold rush with zillions of shit-coins really throwing off the signal to noise ratio

This period will pass. Blockchain tech is maturing (PoS replacing PoW, throughput increasing, formal verification, on-chain governance, etc). Most of the shit-coins will disappear (a common headline these days is exchange X delisting NN coins because they're worthless). Things will consolidate, the really valuable tech will bubble to the top.

If you follow the news, you'd know there's a lot of stuff in the works, from major corporations to governments trialing blockchain for different purposes. Now, you can take a philosophical position about blockchain and say it's worthless, but the rest of the world doesn't seem to care and its widespread adoption is beginning to look like a foregone conclusion.

> In energy for instance, much talk about the financial aspect of a blockchain-based energy solution but absolutely zero talk of how the physical grid and infrastructure would engage to support the financial activity.

http://news.trust.org/item/20180828095937-yg29h/

This is a project trialing in Bangkok. Excess electricity from private solar is sold off automatically.

> Helping it along is blockchain, the distributed ledger technology that underpins bitcoin currency, which offers a transparent way to handle complex transactions between users, producers, and even traders and utilities.

> Blockchain also saves individuals the drudgery of switching between sending power and receiving it, said Martin.

I don't have any details, but it seems they've figured out how 'energy on blockchain' actually works. I have heard the project has been successful enough that city decided to tax them to the point of being unprofitable (will likely correct itself in the future, was probably just a knee jerk reaction).

Re: How Blockchain Works

#90

Post by sparkzilla » Wed, Sep 26, 2018, 4:38 PM UTC

the_snooze wrote: post #75

passiveincomelg wrote: post #72

Earlier quoted context omitted.

verified how?

And what exactly are you verifying?

In its most basic form, we verify that data extracted from news articles matches what has been reported. So, when we extract the data "Trump, Speech, Alabama, Immigration" from an article, then it has to match the reporting in that original source, which may have included a sentence like, "Trump gives a speech in Alabama about immigration".

To avoid the verification process being gamed we split up the data and send pieces to random people across the across the network. So, someone may be asked "Is this article about Trump?" and the next person may be asked "Which state is this sentence about?". They may not even see the whole original article.