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Blockchains: How They Work and Why They’ll Change the World

spectrum.ieee.org

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Re: Blockchains: How They Work and Why They’ll Change the World

#71

Post by rotten »

zodiac wrote: post #57
rotten wrote: post #35

My understanding is that blockchain truth is determined via a majority vote. What I'm really not clear on is how someone with a botnet can't simply take over a blockchain. With such large sums of cash at stake, it seems like a serious hacker would be much more interested in controlling a blockchain than doing silly DDOS attacks on some corporate website that slighted them.

In normal PoW, if you own a botnet, unless your botnet has a significant % (something like 25-51% depend9ng on details) of global hash power you're economically incentiviced to work on the main chain rather than try to "take over" the network

PoW ?

Re: Blockchains: How They Work and Why They’ll Change the World

#72

Post by rotten »

gbersac wrote: post #38
rotten wrote: post #35

My understanding is that blockchain truth is determined via a majority vote. What I'm really not clear on is how someone with a botnet can't simply take over a blockchain. With such large sums of cash at stake, it seems like a serious hacker would be much more interested in controlling a blockchain than doing silly DDOS attacks on some corporate website that slighted them.

For that you need to have more than half of the hash power of the blockchain, which means, for bitcoin at least, billions of hardware investment. A hacker can't have such power.

Many blockchain applications I've seen aren't distributed over millions of computer systems. Thousands, maybe. Hundreds for some.

Re: Blockchains: How They Work and Why They’ll Change the World

#73

Post by dragonwriter »

rotten wrote: post #71
zodiac wrote: post #57

Earlier quoted context omitted.

In normal PoW, if you own a botnet, unless your botnet has a significant % (something like 25-51% depend9ng on details) of global hash power you're economically incentiviced to work on the main chain rather than try to "take over" the network

PoW ?

“Prisoners of War”; in Aztec cryptocurrency mining, blocks are allocated based on captives taken in ritual combat, who are then sacrificed to prevent double counting.

Alternatively, “proof of work”, as used in Bitcoin.

Re: Blockchains: How They Work and Why They’ll Change the World

#74

Post by lambdadmitry »

TheReveller wrote: post #5

From the article: Can a blockchain find people offering rides, link them up with people who are trying to go somewhere, and give the two parties a transparent platform for payment? Can a blockchain act as a repository and a replay platform for TV shows, movies, and other digital media while keeping track of royalties and paying content creators? Can a blockchain check the status of airline flights and pay travelers a…

But there is no need for the whole mining thing if the only transparency is needed.

- publish all "transactions" (of any nature)

- hash (transaction | hash of previous transaction) and sign the hash

- publish signed hashes along the transactions

- give customers back signed hashes of their transactions

This way you have a system with proovable immutability and guaranteed inclusion into the transaction log. If anyone can come up with a signed hash of a transaction not in the log, it means the system isn't trustworthy and should be punished, through legal or market means.

By the way, we already have a system like this in place: Certificate Transparency. There is no way one can buy "tokens" in such model though, so there is no incentive to hype it ¯\_(ツ)_/¯

Re: Blockchains: How They Work and Why They’ll Change the World

#75

Post by spookthesunset »

DennisP wrote: post #58
simias wrote: post #52

Earlier quoted context omitted.

I don't think the parent is a luddite for questioning very emphatic and rather baseless claims. The strawman you build is unwarranted IMO. Household computers were a thing in science fiction long before they were possible and I don't recall anybody doubting you could eventually transmit movies over the internet in a reasonable amount of time. Then you continue with the usual hand waving when people point out weakness…

Regarding third parties, on a blockchain you don't have to trust them to hold your money. You can set up a 2-of-3 scheme where if the two primaries agree then the third party never gets involved, and if they disagree then the third party decides where the money goes, and only then gets a cut. Advantage: in the absence of a dispute, this system is free.

> this system is free.

Free? Who pays for the blockchain? Last I looked into it, each transaction requires about enough electricity to power a house for an entire day. That isn't very free.

Re: Blockchains: How They Work and Why They’ll Change the World

#76

Post by smokeyj »

endymi0n wrote: post #48
zilian wrote: post #45

Earlier quoted context omitted.

Thank you for your comment. Looking at all the doubt and hate about blockchain & cryptocurrencies on HN lately, I personally can't help but wonder where have all innovators gone.

Confirmation Bias at work. You're invested, so you want it to take off. Yet none of those blockchain enthusiasts could tell me a single USP that blockchains had over storage in a normal database on any concrete use case, with the sole exception of cryptocurrencies. And the reason is simple: all those applications have none of the properties and problems the blockchain solves - which is an elegant niche solution tailo…

Most of the practical use cases are illegal developed nations (because fundraising should be guarded for the elite). But there will be a developing nation that adopts the token economy, allowing for global crypto liquidity to flood in and be put to productive use. Stocks, bonds, notes, everything will be tradable on the global marketplace without KYC AML garbage. Just the free flow of capital to where it's needed most.

Re: Blockchains: How They Work and Why They’ll Change the World

#77

Post by spookthesunset »

wildsatchmo wrote: post #44
TheReveller wrote: post #5

From the article: Can a blockchain find people offering rides, link them up with people who are trying to go somewhere, and give the two parties a transparent platform for payment? Can a blockchain act as a repository and a replay platform for TV shows, movies, and other digital media while keeping track of royalties and paying content creators? Can a blockchain check the status of airline flights and pay travelers a…

Looking at all these pessimistic comments I can't help but wonder if this is what the op eds in the newspaper looked like while the internet was being built. "its too slow, and even with our best compression transferring a movie would take a month. Not gonna happen. Computers are too expensive for most households." etc. If you want to keep middle men in between most things that we could potentially do programmaticall…

> If you go the traditional route, you will always have a company in the middle, taking their cut or selling you out behind the scenes.

The free market sure seems to be okay with this. Those middle men provide valuable services like chargebacks, lines of credit, the ability to quickly provide large sums of money without using wheelbarrows to cart them around.

> I'm on the hype train.

You, and almost every other blockchain proponent are so blinded by hype and greed you can't see the very real, very fundamental flaws in bitcoin and "the blockchain". Bitcoin attracts the perfect intersection of people who don't understand economics, math, computer science, finance, business, sociology, or politics. Bitcoin is deeply flawed in all those areas.

Re: Blockchains: How They Work and Why They’ll Change the World

#78

Post by notahacker »

acdha wrote: post #70
wildsatchmo wrote: post #44

Earlier quoted context omitted.

Looking at all these pessimistic comments I can't help but wonder if this is what the op eds in the newspaper looked like while the internet was being built. "its too slow, and even with our best compression transferring a movie would take a month. Not gonna happen. Computers are too expensive for most households." etc. If you want to keep middle men in between most things that we could potentially do programmaticall…

> I'm on the hype train That’s the intellectual blind spot which is making this so hard to understand: you’re invested in the technology and want to see it succeed, which means you’re inclined to minimize every downside and boost every possible use without asking whether something is better in addition to being possible. Being old enough to remember when the internet was starting to go mainstream, there were op-eds l…

I think the key thing is that even without understanding the technology most consumers could see "before I couldn't get access to this information/correspondence/map/ticket/catalogue/advice/news/opinion/porn and now I can" as an obvious life enhancement in a way which having anonymous miners as counterparties rather than the company providing the service and their bank isn't (not even if expressed in terms of a 3% fee reduction). Whereas with blockchain it seems like it's often the evangelists not understanding the consumers: to use examples from the article, I really care that flight delay information is easily available which is why the internet was much better than call centres but I really don't care whether it uses a distributed database or not and wouldn't fly with anyone I worried wouldn't honour the terms of my ticket. I care that ridesharing services have good availability, routing and safety, I really don't want them to be transparent about my location and payments to any interested party.

Now, there are many technologies which are very useful for certain use cases despite the consumer failing to grasp what's going on behind the scenes, from Java VMs to graph databases to torrents, but certain things tend to be true of them (i) they weren't as exciting opportunities as the internet even if billion dollar businesses were built on them (ii) the developers explaining why existing solutions were good enough if not more optimal in many respects were often right.

Re: Blockchains: How They Work and Why They’ll Change the World

#79

Post by notahacker »

chrisco255 wrote: post #66
notahacker wrote: post #33

Earlier quoted context omitted.

Even in a world in which taxis and other institutions are corrupt, it stretches credulity that my real concern when getting a late night taxi is that the merchant service might run away with my $25 and my credit card company might not refund me. I've been in countries where there are major trust issues with taxis, and the very worst case I could imagine would be a service which signals to anyone watching that I'm on…

Trustless doesn't mean reputationless. A blockchain based Uber-like service would function similarly with reviews by former passengers for individual drivers.

Sure, but my point is that the disadvantage of broadcasting to the entire world that I'm on a street corner in Quito in the early hours of a Sunday morning with a smartphone full of cryptocurrency (and for other reasons, having a public record of the details of every ride I've ever taken) is likely more of a concern than reducing the cost/trust of the dispatch/vetting service.

Re: Blockchains: How They Work and Why They’ll Change the World

#80

Post by volkk »

spookthesunset wrote: post #77
wildsatchmo wrote: post #44

Earlier quoted context omitted.

Looking at all these pessimistic comments I can't help but wonder if this is what the op eds in the newspaper looked like while the internet was being built. "its too slow, and even with our best compression transferring a movie would take a month. Not gonna happen. Computers are too expensive for most households." etc. If you want to keep middle men in between most things that we could potentially do programmaticall…

> If you go the traditional route, you will always have a company in the middle, taking their cut or selling you out behind the scenes. The free market sure seems to be okay with this. Those middle men provide valuable services like chargebacks, lines of credit, the ability to quickly provide large sums of money without using wheelbarrows to cart them around. > I'm on the hype train. You, and almost every other block…

> Bitcoin attracts the perfect intersection of people who don't understand economics, math, computer science, finance, business, or politics. Bitcoin is deeply flawed in all those areas.

i can somewhat +1 this just based on anecdotal evidence. a bunch of guys released an ICO and gathered about 15 mil in funding who ive met. i expected them to be extremely smart but i've found that they lucked out and simply wrote up some docs coding barely anything. the idea...seems cool? but i think they're in way over their heads based on what i've gathered from speaking with them. ICOs seem like a crazy scam

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