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How Blockchain Works

blockchain.mit.edu

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Re: How Blockchain Works

#111

Post by thedancollins »

romaniv wrote: post #102
prostoalex wrote: post #65

Earlier quoted context omitted.

> The concept is truly revolutionary In what way? Publishing a DB dump with a checksum has been around for decades, and doesn't require a new user to download an entire history of deltas from day 1.

I'm curious about this as well. No one seem to be talking about specific attacks mitigated by blockchains as opposed to authorities signing current state. The definition implies that if someone says "I'm on block 1000" they cannot create altered version of history without touching all the blocks after the change. But how is this useful? If there is a disagreement about the last block, majority wins, right? So couldn'…

FWIW, if a single actor could take command of more than 50% of a chain's hashrate then yes, they could take over and rewrite history. The theory was that this would be far too expensive in power and time for any such attack to succeed and if it did - the chain would simply fork at time pervious to the attack and the person that had taken the now defunct chain over would be the only person operating on that blockchain.

Re: How Blockchain Works

#112

Post by abraham_lincoln »

Moodles wrote: post #43
the_snooze wrote: post #23

Earlier quoted context omitted.

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 da…

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.

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.

Re: How Blockchain Works

#113

Post by decentralised »

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…

The reason to build blockchain based systems is the desire for architectural decentralisation and trustless systems. Most use cases you can think of you have already seen elsewhere, hence why you can think about them right?

To give you a concrete example of a use case that can't be met without a blockchain, I'd suggest looking into Aragon and their DAO (decentralised autonomous organisation) software.

Re: How Blockchain Works

#114

Post by thedancollins »

prostoalex wrote: post #91
thedancollins wrote: post #73

Earlier quoted context omitted.

Because it finally provides a mechanism by which bad actors on a network could face repercussions for their activity. Consider how different the internet would be if hyperlinks were two-way rather than one-way. Again, it is not only about data, it is about the speed of transactability that would result when value could be exchanged instantaneously with radical transparency behind the actors on the chain. Bankers go a…

> it is about the speed of transactability As somebody pointed out https://news.ycombinator.com/item?id=18076542 high transaction throughput is not exactly the killer feature of modern-day blockchains.

Well ok, buit I was talking about transactability - not throughput. I have stated numerous times that the tech struggles to be viable at scale. On Bitcoin's blockchain you can transact and settle in 10 minutes. That beats 2 to 3 days all day long in a fiat-based system.

Re: How Blockchain Works

#115

Post by abraham_lincoln »

hef19898 wrote: post #78
the_snooze wrote: post #23

Earlier quoted context omitted.

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 da…

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…

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.

Re: How Blockchain Works

#116

Post by thedancollins »

romaniv wrote: post #110
thedancollins wrote: post #73

Earlier quoted context omitted.

Because it finally provides a mechanism by which bad actors on a network could face repercussions for their activity. Consider how different the internet would be if hyperlinks were two-way rather than one-way. Again, it is not only about data, it is about the speed of transactability that would result when value could be exchanged instantaneously with radical transparency behind the actors on the chain. Bankers go a…

>Because it finally provides a mechanism by which bad actors on a network could face repercussions for their activity. Would this require globally broadcasting all transaction? If yes, wouldn't globally broadcasting all transaction give you a lot of transparency anyway?

A blockchain is a ledger of all transactions, yes. Son the result is transparency.

Re: How Blockchain Works

#117

Post by decentralised »

romaniv wrote: post #102
prostoalex wrote: post #65

Earlier quoted context omitted.

> The concept is truly revolutionary In what way? Publishing a DB dump with a checksum has been around for decades, and doesn't require a new user to download an entire history of deltas from day 1.

I'm curious about this as well. No one seem to be talking about specific attacks mitigated by blockchains as opposed to authorities signing current state. The definition implies that if someone says "I'm on block 1000" they cannot create altered version of history without touching all the blocks after the change. But how is this useful? If there is a disagreement about the last block, majority wins, right? So couldn'…

The attacks that blockchain can protect against are:

- Fraud

- DDoS

- Censorship

The usefulness of a consensus protocol is that no one party can be trusted to have the most up-to-date AND valid blockchain. Every node has the incentive to cheat and the consensus rules define a method of evaluating the proposed chain of blocks and determine it's "trustworthiness". In PoW this is often an algorithm like Greedy Heaviest Observed Sub-Tree (GHOST) which favours the fork with the highest accumulated work.

This is why it's important that mining is an expensive activity, to discourage attackers from wasting thousands of euros in electricity and then losing the block reward payment.

Re: How Blockchain Works

#118

Post by thedancollins »

vec wrote: post #100
thedancollins wrote: post #73

Earlier quoted context omitted.

Because it finally provides a mechanism by which bad actors on a network could face repercussions for their activity. Consider how different the internet would be if hyperlinks were two-way rather than one-way. Again, it is not only about data, it is about the speed of transactability that would result when value could be exchanged instantaneously with radical transparency behind the actors on the chain. Bankers go a…

> Bankers go away People will still need loans. People will still want low risk investment vehicles to "store" their wealth in. At least some sizable number of them will want an institutional actor to handle operational security and insure against key loss. > auditors go away The blockchain mostly guarantees that a ledger hasn't been tampered with, but it doesn't guarantee that the transactions were correct and compl…

You are not grasping the import of being able to exchange value WITHOUT a banking system in place.

As for the credit requirements comment, yes - good point. But in the case of a micro-transaction, realtime agreement. I can consume 15 minutes of power and pay for it at 15:01. A credit requirement still exists -0 but it is one second as opposed to 60-90 days worth of power. This idea assumes many things into existence that do no currently exist - I am merely offering the idea as a thought experiment. Blockchain could make everything pay-as-you-consume.

Re: How Blockchain Works

#119

Post by lawn »

thedancollins wrote: post #99
lawn wrote: post #76

Earlier quoted context omitted.

The term blockchain should come with a way to decide consensus, like proof-of-work or possibly proof-of-stake. This is a solution to decentralized consensus which is a truly revolutionary concept.

From a technical perspective, yes. But the case for blockchain is difficult to make from a technical perspective so I do not bother talking about it. The tech struggles to be viable. With that said, everything is impossible .. until it is not. Somebody will figure it out.

What do you mean struggles to be viable? Cryptocurrencies is already viable and used in a lot of places. If you mean other usages of blockchain I do agree.

And please don't bring up scaling (it's already viable today so the future is irrelevant to the point) or high fess (caused by Bitcoin's incompetent devs).

Re: How Blockchain Works

#120

Post by [deleted] »

thedancollins wrote: post #111
romaniv wrote: post #102

Earlier quoted context omitted.

I'm curious about this as well. No one seem to be talking about specific attacks mitigated by blockchains as opposed to authorities signing current state. The definition implies that if someone says "I'm on block 1000" they cannot create altered version of history without touching all the blocks after the change. But how is this useful? If there is a disagreement about the last block, majority wins, right? So couldn'…

FWIW, if a single actor could take command of more than 50% of a chain's hashrate then yes, they could take over and rewrite history. The theory was that this would be far too expensive in power and time for any such attack to succeed and if it did - the chain would simply fork at time pervious to the attack and the person that had taken the now defunct chain over would be the only person operating on that blockchain…

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