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What exactly is the specific use case where Proof of Work blockchain are appropriate? Consensus in that design is: 1. Perhaps the single most expensive consen

What exactly is the specific use case where Proof of Work blockchain are appropriate? Consensus in that design is: 1. Perhaps the single most expensive consensus algorithm ever designed. 2. Deliberately one of the slowest. 3. Does not actually provide trustless consensus once 1/3 of the miner nodes decide to collude. Other than "our data is a merkle tree but you have to trust us to submit transactions to it", and "a currency system with a failed promise to deliver either scale or trustless consensus" what, is the proper application?

dozzie 9y ago
> Consensus in [proof of work blockchain] design is: > 1. Perhaps the single most expensive consensus algorithm ever designed. It's like arguing that bubblesort is one of the most expensive graph traversal algorithms. It's not, because it's a protocol for document timestamping, not establishing a consensus. > 2. Deliberately one of the slowest. Indeed. It was designed so verification of the timestamps is much, much faster than producing them. In previous work, with trusted third party operating a timestamping service, it was enough to control a single service, so there was no need to design this into the very data structure. > 3. Does not actually provide trustless consensus once 1/3 of the miner nodes decide to collude. Indeed it does not, because it was never designed as a consensus protocol. > [...] what, is the proper application [of blockchain]? When you need to establish an order in a sequence of related documents, like with trade contracts. Outside of this very narrow purpose, blockchain is pretty much useless.
- KirinDave 9y ago
  > Indeed it does not, because it was never designed as a consensus protocol. What exactly do you think a distributed ledger is other than a normal ledger and a trustless consensus protocol?
  - dozzie 9y ago
    > What exactly do you think a distributed ledger is other than a normal ledger and a trustless consensus protocol? There is no such thing among cryptographic protocols as "distributed ledger". The ledger is implemented on top of document timestamping and while required for Bitcoin, it doesn't exist for blockchain data structure. It's like calling HTTPs a cryptographic protocol for serving files. About this "trustless consensus" part, how do you define "consensus" and how does it relate to what computer science calls "consensus" with its most prominent problem of Byzantine generals, especially with the impossibility proof (the one that talks about 1/3 traitors)?
    - KirinDave 9y ago
      I'm sorry, but I cannot even work out what your post is about. Firstly: the single most important function of the Bitcoin network is to maintain a ledger that prevents double spends. Ethereum's charter is not so easily summed up bit it shares a responsibility here. The tools Bitcoin uses to do this do indeed stem from cryptographic research, but the primary function of a blockchain is not to certify the past but to come to consensus on the immedate future. No elliptic curve will do that for you. It is a distributed algorithm leveraging guarantees given by cryptographic primitives. Every expert accepts it as such. As for your final note: multiple "solutions" for the Byzantine generals exist and have been published for years. Many of them give better guarantees than what a post-selfish-mining PoW blockchain gives you. If your argument was, "It was never possible to come to consensus to begin with" then what are we talking about. If your argument is that it works fine, you should refute the cited paper directly. If your argument is that it's fine despite the flaws, I do not agree.
      - dozzie 9y ago
        > I'm sorry, but I cannot even work out what your post is about. The point boils down to this: you throw the "consensus" term left and right. The term has a concrete meaning in computer science, and you use it incorrectly, so stop doing that. > As for your final note: multiple "solutions" for the Byzantine generals exist and have been published for years. Many of them give better guarantees than what a post-selfish-mining PoW blockchain gives you. Note that the Byzantine generals problem has a rigorous proof that says you cannot have a consensus if loyal nodes don't outnumber the traitors by more than 2:1 (so you need 2/3 + 1 loyal nodes), and the proof is not about just the original algorithm Lamport et al. designed, it's about the consensus problem itself. Where does the blockchain's "50% + 1" stands against that if blockchain was supposed to be a consensus algorithm? > If your argument was, [...] If your argument is [...] If your argument is [...] My whole point is "don't use the 'consensus' term incorrectly" and "call the blockchain what it is, i.e. timestamping protocol".
        KirinDave 9y ago
        > My whole point is "don't use the 'consensus' term incorrectly" and "call the blockchain what it is, i.e. timestamping protocol". The time is 35. If you don't agree, we'll have to come sort of... Oh wait I'm not supposed to use that word.
ozmbie 9y ago
If you can invent a reliable alternative to proof-of-work distributed consensus there is a multi-billion dollar opportunity there. It’s inefficient, but before bitcoin came along there was no way to even do it. An inefficient way is better than no way at all. Some other cryptocurrencies are trying alternatives. But none have been as “battle hardened” as bitcoin. Follow the core developers and you’ll see their focus is on creating an open distributed platform. It’s up to us to figure out what to use it for.
- KirinDave 9y ago
  Can I also invent a system that's been proven to not safely guarnatee consensus for years, and trust everyone to ignore it? If so, I've got a thrilling investment opportunity for you.
- curun1r 9y ago
  > An inefficient way is better than no way at all Really, why? IMHO, there's a pretty compelling argument to be made that Bitcoin and the other cryptocurrencies have had a significantly net-negative impact on the world, from facilitating scams and other illegal activity to now having to worry that sites we visit will monetize by stealing CPU cycles to the significant impact on climate change, these technologies have caused a lot more harm than benefit. And all the while, they haven't even figured out how to build a ledger that can scale to day-to-day transactions. My bet is that the whole thing ends up being a tax on people who've forgotten their 17th century Dutch history.
  - __s 9y ago
    We should've drawn the line in the sand back with 56 bit key limits
  - knocte 9y ago
    > from facilitating scams and other illegal activity The same was said over and over on the nascent days of the internet, about how it facilitated anonymity so easily and how it would be used by criminals. > by stealing CPU cycles Difficulty in bitcoin mining is raising all the time (because of the competition among miners). This is why nobody mines nowadays with CPUs or GPUs but with ASICs. The fact that some sites are trying to achieve some decent mining hashrate by pulling the amount of visitors of a website is a naive move that will soon be off-set by even more raising levels of difficulty. Soon this will not be profitable at all, even if your website was the 1st in Google's page rank. > to the significant impact on climate change I like that skeptics raise this point, because: 1) The cryptocurrency mining industry is the fastest one to chase energy-efficient solutions. As soon as a device consumes less electricity, it's adopted widely because of the huge incentives to do so (e.g. CPU->GPU->ASIC). 2) Compare the electricity spent by the entire banking industry with the electricity spent by the entire crypto-mining industry. Now guess what's more efficient.
booppoob 9y ago
Please provide sources and/or elaboration for/on the following: * Deliberate slowness. * Comparative slowness (given the problem space). * 1/3 collusion breaking trust-less consensus. * A definition of "us", "trust" and "scale" for your 6th line.
- AlexCoventry 9y ago
  > Deliberate slowness. As OP article alludes, bitcoin difficulty is tuned for a very long interval between blocks, to reduce the risk of nearly-simultaneous "uncle" blocks. Other blockchains such as Ethereum have seemingly successful alternative approaches. IMO the article has a very limited perspective on blockchain technology. It's understandable, since the space is exploding and very hard to keep a handle on, but I think it should be less sweeping in its claims.
  - KirinDave 9y ago
    That doesn't really solve the problem at all though.
    - AlexCoventry 9y ago
      Ethereum beautifully solved the problem of "how do I cheaply make a token with trustless trading semantics?", and it's been used to raise billions of dollars of funding. So that might depend on the problem you're talking about. There's an enormous amount of interesting blockchain technology, so sweeping dismissals of it tend to be lazy and ignorant.
      - pjc50 9y ago
        > to raise billions of dollars of funding How much of that was neither exit scammed nor lost to contract bugs?
        opportune 9y ago
        how much of the internet was dedicated to porn and funny pictures?
wpietri 9y ago
I have been asking that for years without getting a good answer. It's a really cool technology! I wanted to use it for something! But cryptotulips aside, every real-world use case I've looked at can be solved some other way (e.g., real-time published transaction logs). Humans are pretty good at creating trust contexts (see, e.g., 99% of commerce), and they're quite averse to doing anything significant in truly trustless contexts.
- kybernetikos 9y ago
  Almost nothing is a unique solution to a set of problems. Just because the problems that distributed ledger technologies address can be solved in a different way doesn't mean that to do so is the right business decision.
  - paulgb 9y ago
    Sure, but PoW is (by design) computationally expensive, so any blockchain solution has the burden of showing why it's sufficiently better than the alternative to merit the extra cost.
    - Scarblac 9y ago
      Another problem is that if your nice blockchain has N computers in it, someone can go to AWS and add N+1 and take over your network. You basically have to blow more money on PoW than the network is worth _constantly_. Or you can have a "private blockchain", which defeats the purpose entirely.
  - KirinDave 9y ago
    This would be a much better defense if PoW blockchains solved ANY problems. As far as I can tell, they provide inferior guarantees AND performance to existing methodologies and algorithms.
    - ftlio 9y ago
      Is there some other technology out there creating an immutable supply token better than Bitcoin that I don't know about?
colordrops 9y ago
> Does not actually provide trustless consensus once 1/3 of the miner nodes decide to collude. Source? This does not match my understanding of POW blockchains.
- KirinDave 9y ago
  https://news.ycombinator.com/item?id=16898463 https://news.ycombinator.com/item?id=16898463
  - asynchrony 9y ago
    I found this article related to the attack in that paper https://bitcoinmagazine.com/articles/why-bitcoin-mining-pools-aren-t-incentivized-to-broadcast-blocks-quickly-1475249510/ https://bitcoinmagazine.com/articles/why-bitcoin-mining-pool... While I'm not completely convinced that the countermeasure of "spy mining" completely mitigates the attack, it does appear that this is not a new vulnerability. Further, if a pool had all of the hardware under one roof, it wouldn't be possible to spy at all which would reinstate all of the problems outlined in the paper.
    - deleted 9y ago
      [deleted]
    - KirinDave 9y ago
      I don't see how "spy mining" actually helps. It seems a bitter pill to suggest that now we need ANOTHER layer of validation on top of the existing protocol, further increasing Bitcoin's energy cost. And if you believe this mitigates the attack, then "spy selfish miners" must also exist then, keeping parity. Proof of work as implemented now is fatally flawed, and it's primarily a tenant of faith instead of logic that it isn't. Just google "selfish mining debate" and enjoy the plethora of inane and tedious reactions. But also: yes the paper is not at all new. After replication and other checks, the Bitcoin community has gotten up on its high horse, plugged its ears tight with wax, and started signing, "I can't hear you!"
      - 9y ago
deleted 9y ago
[deleted]
msutherl 9y ago
This reads like a rhetorical question – 'what could possibly be the application for something this deliberately bad?' I won't speak for what "blockchain" can or will become, but you might see the hype more clearly by considering the ideology inherent in asking specifically for the "proper application." You imply that you or someone in a position you understand might "apply blockchain" to a "problem," as you commonly understand it. I see "blockchain" more as a movement, which completely evades "application" in the common sense. People building these technologies, and organizations around them, live in a separate world that makes little reference to the broader world of which most of us are a part. They start with distinct priors, which rule out most existing solutions on the grounds that they demand political centralization (see: https://medium.com/@VitalikButerin/the-meaning-of-decentralization-a0c92b76a274 https://medium.com/@VitalikButerin/the-meaning-of-decentrali...). You can summarize this ideology as: 'if there's a sysadmin, the system is broken.' It may very well be the case that they are creating a new world that will be marginalized and outcompeted by incumbent systems and organizations, but that's how I understand what's 'actually going on'.
- pjc50 9y ago
  I admire the principles of decentralization, but I think it's rather like "serverless" - it moves the functionality around in order to pretend. All the cryptocurrencies have pretty "centralized" dev teams; as with Etherum they can fork to decide what history is and most miners will go with that. History is written by whoever has the github.
  - KirinDave 9y ago
    Consensus forking should always exist as an option. The problem with PoW blockchains is not the visible governance options. Those are a very positive feature. The problem is the invisible governance patterns that an unreliable consensus algorithm creates.
  - gruez 9y ago
    >History is written by whoever has the github. Not really, just because a change is pushed to the github repo, doesn't mean the network (and its participants) will automatically accept it. Those unhappy with the changes can always fork the network if they want.
stale2002 9y ago
I mean, you can call it bad, but it provely works for the thing that it intended to solve. That thing being sending censorship resistant, electronic financial transactions. If you don't believe me that this worked, then please go back to 2010 and tell me a better way to donate money to Wikileaks. At the end if the day, I could send money to Wikileaks, and there were no other options that worked at the time. The points that you brought up don't really matter, because Bitcoin has been around for 8+ years and we don't see those attacks happening. I don't care about the theoretical. I care about the practical. Come back to me with that attack vector once it actually happens on the live network, and money going to Wikileaks or whoever ACTUALLY gets censored.
- KirinDave 9y ago
  > I mean, you can call it bad, but it provely works for the thing that it intended to solve. That thing being sending censorship resistant, electronic financial transactions. But it doesn't appear to do so. 1. It cannot meet demand, so folks are recreating existing point to point financial networks and then using the chain in the event of reconciliation. These define a new topology as surely as credit card companies redefined the topology of modern digital economies. 2. It appears that it is very easy to gain a secret majority and do all sorts of nasty things, in addition to freezing out miners. P.S., if I had a magic wand that could make WikiLeaks disappear in a sweeping curtain of sulphuric fire, I'd stick a bell on the top and wave it happily until my doctor informed me my RSI was fatal.
  - stale2002 9y ago
    OK, so it appears that you don't support tools that allow people to get around censorship. That's fine, but that is literally the point of Bitcoin. You just don't like the use case. At the end of the end, it has been working for 8 years, and it is the best tool out there to solve the problem of censorship resistant financial transactions. This is proven by the fact that even though people want to shut down payments to places like Wikileaks they are still happening So the purpose is to subvert people and groups like you, who want to stop these payments, and yet the payments and money still flows. The nasty things that you claim COULD happen, AREN'T. This is proven by the fact that groups like Wikileaks still recieve their money. My definition of "working" has nothing to with theoreticals. It has to do with the practical, historical examples. And the historical example is that these groups are still receiving their money, so by definition it did work. Or in other words, if it really doesn't work, as you claim, the how come it its working? As defined by the fact that it is literally the best existing tool out there for this usecase. (IE, visa and mastercard will block your money, and yet bitcoin still works) If you disagree, fine, go ahead and try to stop my money going to places that you don't want it to (ex, such as Wikileaks). Report it to the NSA or whoever, for supporting "russian propaganda", or whatever. Betcha won't succeed.
niftich 9y ago
In my opinion, the most notable innovation of Bitcoin is the incentive and PoW-reward for the continued upkeep and health of the network, and I often wonder why so much of the literature around blockchains misses or glosses over this fact. The scheme neatly solves the free-rider problem that plagues other distributed systems, where your continued usage of the network can be ensured by your active participation within it.
- Laforet 9y ago
  >The scheme neatly solves the free-rider problem that plagues other permissionless systems. FTFY A parallel example would be various P2P filesharing protocols which was plagued by freeloaders from day 1, and had to come up with various schemes to regulate the user's contribution. The simpler solutions are not exactly Byzantine fault tolerant (user profiles in ed2k) whereas the more elaborate mechanism typically requires a centralised record keeper(private trackers, etc). A lot of the inefficiencies of PoW are necessary to keep the network permissionless, and conversely you don't need PoW if the system has any kind of entry requirement.
KirinDave 9y ago
Just to restate because I was not expecting to have to have this post pop up to top of thread: The selfish mining paper shows a significantly worse result than 1/3. I feel the need to lay this out very plainly because folks may not be in on that joke. It's a joke at 1/3rd because that's sort of a naive threshold of for the BGP anyways. Bitcoin was supposed to provide a stable solution where distributed actors could come to consensus on a ledger. That's how it was sold in the original paper. Majority attacks against the system will always exist, but the paper mentioned proves that the Bitcoin proof of work algorithm is much worse than we realized, and (more troublingly) that bad actors are harder to detect than it was passively assumed.
- watwat1 9y ago
  Citations.
vasilipupkin 9y ago
I think blockstack is one such application: to register an identity without relying on any central party for that. Basically anything where you need to make a very small number of transactions to store information that will be cryptographically secured in a decentralized manner.

dozzie 9y ago

> Consensus in [proof of work blockchain] design is: > 1. Perhaps the single most expensive consensus algorithm ever designed. It's like arguing that bubblesort is one of the most expensive graph traversal algorithms. It's not, because it's a protocol for document timestamping, not establishing a consensus. > 2. Deliberately one of the slowest. Indeed. It was designed so verification of the timestamps is much, much faster than producing them. In previous work, with trusted third party operating a timestamping service, it was enough to control a single service, so there was no need to design this into the very data structure. > 3. Does not actually provide trustless consensus once 1/3 of the miner nodes decide to collude. Indeed it does not, because it was never designed as a consensus protocol. > [...] what, is the proper application [of blockchain]? When you need to establish an order in a sequence of related documents, like with trade contracts. Outside of this very narrow purpose, blockchain is pretty much useless.

KirinDave 9y ago
> Indeed it does not, because it was never designed as a consensus protocol. What exactly do you think a distributed ledger is other than a normal ledger and a trustless consensus protocol?
- dozzie 9y ago
  > What exactly do you think a distributed ledger is other than a normal ledger and a trustless consensus protocol? There is no such thing among cryptographic protocols as "distributed ledger". The ledger is implemented on top of document timestamping and while required for Bitcoin, it doesn't exist for blockchain data structure. It's like calling HTTPs a cryptographic protocol for serving files. About this "trustless consensus" part, how do you define "consensus" and how does it relate to what computer science calls "consensus" with its most prominent problem of Byzantine generals, especially with the impossibility proof (the one that talks about 1/3 traitors)?
  - KirinDave 9y ago
    I'm sorry, but I cannot even work out what your post is about. Firstly: the single most important function of the Bitcoin network is to maintain a ledger that prevents double spends. Ethereum's charter is not so easily summed up bit it shares a responsibility here. The tools Bitcoin uses to do this do indeed stem from cryptographic research, but the primary function of a blockchain is not to certify the past but to come to consensus on the immedate future. No elliptic curve will do that for you. It is a distributed algorithm leveraging guarantees given by cryptographic primitives. Every expert accepts it as such. As for your final note: multiple "solutions" for the Byzantine generals exist and have been published for years. Many of them give better guarantees than what a post-selfish-mining PoW blockchain gives you. If your argument was, "It was never possible to come to consensus to begin with" then what are we talking about. If your argument is that it works fine, you should refute the cited paper directly. If your argument is that it's fine despite the flaws, I do not agree.
    - dozzie 9y ago
      > I'm sorry, but I cannot even work out what your post is about. The point boils down to this: you throw the "consensus" term left and right. The term has a concrete meaning in computer science, and you use it incorrectly, so stop doing that. > As for your final note: multiple "solutions" for the Byzantine generals exist and have been published for years. Many of them give better guarantees than what a post-selfish-mining PoW blockchain gives you. Note that the Byzantine generals problem has a rigorous proof that says you cannot have a consensus if loyal nodes don't outnumber the traitors by more than 2:1 (so you need 2/3 + 1 loyal nodes), and the proof is not about just the original algorithm Lamport et al. designed, it's about the consensus problem itself. Where does the blockchain's "50% + 1" stands against that if blockchain was supposed to be a consensus algorithm? > If your argument was, [...] If your argument is [...] If your argument is [...] My whole point is "don't use the 'consensus' term incorrectly" and "call the blockchain what it is, i.e. timestamping protocol".
      - KirinDave 9y ago
        > My whole point is "don't use the 'consensus' term incorrectly" and "call the blockchain what it is, i.e. timestamping protocol". The time is 35. If you don't agree, we'll have to come sort of... Oh wait I'm not supposed to use that word.

ozmbie 9y ago

If you can invent a reliable alternative to proof-of-work distributed consensus there is a multi-billion dollar opportunity there. It’s inefficient, but before bitcoin came along there was no way to even do it. An inefficient way is better than no way at all. Some other cryptocurrencies are trying alternatives. But none have been as “battle hardened” as bitcoin. Follow the core developers and you’ll see their focus is on creating an open distributed platform. It’s up to us to figure out what to use it for.

KirinDave 9y ago
Can I also invent a system that's been proven to not safely guarnatee consensus for years, and trust everyone to ignore it? If so, I've got a thrilling investment opportunity for you.
curun1r 9y ago
> An inefficient way is better than no way at all Really, why? IMHO, there's a pretty compelling argument to be made that Bitcoin and the other cryptocurrencies have had a significantly net-negative impact on the world, from facilitating scams and other illegal activity to now having to worry that sites we visit will monetize by stealing CPU cycles to the significant impact on climate change, these technologies have caused a lot more harm than benefit. And all the while, they haven't even figured out how to build a ledger that can scale to day-to-day transactions. My bet is that the whole thing ends up being a tax on people who've forgotten their 17th century Dutch history.
- __s 9y ago
  We should've drawn the line in the sand back with 56 bit key limits
- knocte 9y ago
  > from facilitating scams and other illegal activity The same was said over and over on the nascent days of the internet, about how it facilitated anonymity so easily and how it would be used by criminals. > by stealing CPU cycles Difficulty in bitcoin mining is raising all the time (because of the competition among miners). This is why nobody mines nowadays with CPUs or GPUs but with ASICs. The fact that some sites are trying to achieve some decent mining hashrate by pulling the amount of visitors of a website is a naive move that will soon be off-set by even more raising levels of difficulty. Soon this will not be profitable at all, even if your website was the 1st in Google's page rank. > to the significant impact on climate change I like that skeptics raise this point, because: 1) The cryptocurrency mining industry is the fastest one to chase energy-efficient solutions. As soon as a device consumes less electricity, it's adopted widely because of the huge incentives to do so (e.g. CPU->GPU->ASIC). 2) Compare the electricity spent by the entire banking industry with the electricity spent by the entire crypto-mining industry. Now guess what's more efficient.

booppoob 9y ago

Please provide sources and/or elaboration for/on the following: * Deliberate slowness. * Comparative slowness (given the problem space). * 1/3 collusion breaking trust-less consensus. * A definition of "us", "trust" and "scale" for your 6th line.

AlexCoventry 9y ago
> Deliberate slowness. As OP article alludes, bitcoin difficulty is tuned for a very long interval between blocks, to reduce the risk of nearly-simultaneous "uncle" blocks. Other blockchains such as Ethereum have seemingly successful alternative approaches. IMO the article has a very limited perspective on blockchain technology. It's understandable, since the space is exploding and very hard to keep a handle on, but I think it should be less sweeping in its claims.
- KirinDave 9y ago
  That doesn't really solve the problem at all though.
  - AlexCoventry 9y ago
    Ethereum beautifully solved the problem of "how do I cheaply make a token with trustless trading semantics?", and it's been used to raise billions of dollars of funding. So that might depend on the problem you're talking about. There's an enormous amount of interesting blockchain technology, so sweeping dismissals of it tend to be lazy and ignorant.
    - pjc50 9y ago
      > to raise billions of dollars of funding How much of that was neither exit scammed nor lost to contract bugs?
      - opportune 9y ago
        how much of the internet was dedicated to porn and funny pictures?

wpietri 9y ago

I have been asking that for years without getting a good answer. It's a really cool technology! I wanted to use it for something! But cryptotulips aside, every real-world use case I've looked at can be solved some other way (e.g., real-time published transaction logs). Humans are pretty good at creating trust contexts (see, e.g., 99% of commerce), and they're quite averse to doing anything significant in truly trustless contexts.

kybernetikos 9y ago
Almost nothing is a unique solution to a set of problems. Just because the problems that distributed ledger technologies address can be solved in a different way doesn't mean that to do so is the right business decision.
- paulgb 9y ago
  Sure, but PoW is (by design) computationally expensive, so any blockchain solution has the burden of showing why it's sufficiently better than the alternative to merit the extra cost.
  - Scarblac 9y ago
    Another problem is that if your nice blockchain has N computers in it, someone can go to AWS and add N+1 and take over your network. You basically have to blow more money on PoW than the network is worth _constantly_. Or you can have a "private blockchain", which defeats the purpose entirely.
- KirinDave 9y ago
  This would be a much better defense if PoW blockchains solved ANY problems. As far as I can tell, they provide inferior guarantees AND performance to existing methodologies and algorithms.
  - ftlio 9y ago
    Is there some other technology out there creating an immutable supply token better than Bitcoin that I don't know about?

colordrops 9y ago

> Does not actually provide trustless consensus once 1/3 of the miner nodes decide to collude. Source? This does not match my understanding of POW blockchains.

KirinDave 9y ago
https://news.ycombinator.com/item?id=16898463 https://news.ycombinator.com/item?id=16898463
- asynchrony 9y ago
  I found this article related to the attack in that paper https://bitcoinmagazine.com/articles/why-bitcoin-mining-pools-aren-t-incentivized-to-broadcast-blocks-quickly-1475249510/ https://bitcoinmagazine.com/articles/why-bitcoin-mining-pool... While I'm not completely convinced that the countermeasure of "spy mining" completely mitigates the attack, it does appear that this is not a new vulnerability. Further, if a pool had all of the hardware under one roof, it wouldn't be possible to spy at all which would reinstate all of the problems outlined in the paper.
  - deleted 9y ago
    [deleted]
  - KirinDave 9y ago
    I don't see how "spy mining" actually helps. It seems a bitter pill to suggest that now we need ANOTHER layer of validation on top of the existing protocol, further increasing Bitcoin's energy cost. And if you believe this mitigates the attack, then "spy selfish miners" must also exist then, keeping parity. Proof of work as implemented now is fatally flawed, and it's primarily a tenant of faith instead of logic that it isn't. Just google "selfish mining debate" and enjoy the plethora of inane and tedious reactions. But also: yes the paper is not at all new. After replication and other checks, the Bitcoin community has gotten up on its high horse, plugged its ears tight with wax, and started signing, "I can't hear you!"
    - 9y ago

deleted 9y ago

[deleted]

msutherl 9y ago

This reads like a rhetorical question – 'what could possibly be the application for something this deliberately bad?' I won't speak for what "blockchain" can or will become, but you might see the hype more clearly by considering the ideology inherent in asking specifically for the "proper application." You imply that you or someone in a position you understand might "apply blockchain" to a "problem," as you commonly understand it. I see "blockchain" more as a movement, which completely evades "application" in the common sense. People building these technologies, and organizations around them, live in a separate world that makes little reference to the broader world of which most of us are a part. They start with distinct priors, which rule out most existing solutions on the grounds that they demand political centralization (see: https://medium.com/@VitalikButerin/the-meaning-of-decentralization-a0c92b76a274 https://medium.com/@VitalikButerin/the-meaning-of-decentrali...). You can summarize this ideology as: 'if there's a sysadmin, the system is broken.' It may very well be the case that they are creating a new world that will be marginalized and outcompeted by incumbent systems and organizations, but that's how I understand what's 'actually going on'.

pjc50 9y ago
I admire the principles of decentralization, but I think it's rather like "serverless" - it moves the functionality around in order to pretend. All the cryptocurrencies have pretty "centralized" dev teams; as with Etherum they can fork to decide what history is and most miners will go with that. History is written by whoever has the github.
- KirinDave 9y ago
  Consensus forking should always exist as an option. The problem with PoW blockchains is not the visible governance options. Those are a very positive feature. The problem is the invisible governance patterns that an unreliable consensus algorithm creates.
- gruez 9y ago
  >History is written by whoever has the github. Not really, just because a change is pushed to the github repo, doesn't mean the network (and its participants) will automatically accept it. Those unhappy with the changes can always fork the network if they want.

stale2002 9y ago

I mean, you can call it bad, but it provely works for the thing that it intended to solve. That thing being sending censorship resistant, electronic financial transactions. If you don't believe me that this worked, then please go back to 2010 and tell me a better way to donate money to Wikileaks. At the end if the day, I could send money to Wikileaks, and there were no other options that worked at the time. The points that you brought up don't really matter, because Bitcoin has been around for 8+ years and we don't see those attacks happening. I don't care about the theoretical. I care about the practical. Come back to me with that attack vector once it actually happens on the live network, and money going to Wikileaks or whoever ACTUALLY gets censored.

KirinDave 9y ago
> I mean, you can call it bad, but it provely works for the thing that it intended to solve. That thing being sending censorship resistant, electronic financial transactions. But it doesn't appear to do so. 1. It cannot meet demand, so folks are recreating existing point to point financial networks and then using the chain in the event of reconciliation. These define a new topology as surely as credit card companies redefined the topology of modern digital economies. 2. It appears that it is very easy to gain a secret majority and do all sorts of nasty things, in addition to freezing out miners. P.S., if I had a magic wand that could make WikiLeaks disappear in a sweeping curtain of sulphuric fire, I'd stick a bell on the top and wave it happily until my doctor informed me my RSI was fatal.
- stale2002 9y ago
  OK, so it appears that you don't support tools that allow people to get around censorship. That's fine, but that is literally the point of Bitcoin. You just don't like the use case. At the end of the end, it has been working for 8 years, and it is the best tool out there to solve the problem of censorship resistant financial transactions. This is proven by the fact that even though people want to shut down payments to places like Wikileaks they are still happening So the purpose is to subvert people and groups like you, who want to stop these payments, and yet the payments and money still flows. The nasty things that you claim COULD happen, AREN'T. This is proven by the fact that groups like Wikileaks still recieve their money. My definition of "working" has nothing to with theoreticals. It has to do with the practical, historical examples. And the historical example is that these groups are still receiving their money, so by definition it did work. Or in other words, if it really doesn't work, as you claim, the how come it its working? As defined by the fact that it is literally the best existing tool out there for this usecase. (IE, visa and mastercard will block your money, and yet bitcoin still works) If you disagree, fine, go ahead and try to stop my money going to places that you don't want it to (ex, such as Wikileaks). Report it to the NSA or whoever, for supporting "russian propaganda", or whatever. Betcha won't succeed.

niftich 9y ago

In my opinion, the most notable innovation of Bitcoin is the incentive and PoW-reward for the continued upkeep and health of the network, and I often wonder why so much of the literature around blockchains misses or glosses over this fact. The scheme neatly solves the free-rider problem that plagues other distributed systems, where your continued usage of the network can be ensured by your active participation within it.

Laforet 9y ago
>The scheme neatly solves the free-rider problem that plagues other permissionless systems. FTFY A parallel example would be various P2P filesharing protocols which was plagued by freeloaders from day 1, and had to come up with various schemes to regulate the user's contribution. The simpler solutions are not exactly Byzantine fault tolerant (user profiles in ed2k) whereas the more elaborate mechanism typically requires a centralised record keeper(private trackers, etc). A lot of the inefficiencies of PoW are necessary to keep the network permissionless, and conversely you don't need PoW if the system has any kind of entry requirement.

KirinDave 9y ago

Just to restate because I was not expecting to have to have this post pop up to top of thread: The selfish mining paper shows a significantly worse result than 1/3. I feel the need to lay this out very plainly because folks may not be in on that joke. It's a joke at 1/3rd because that's sort of a naive threshold of for the BGP anyways. Bitcoin was supposed to provide a stable solution where distributed actors could come to consensus on a ledger. That's how it was sold in the original paper. Majority attacks against the system will always exist, but the paper mentioned proves that the Bitcoin proof of work algorithm is much worse than we realized, and (more troublingly) that bad actors are harder to detect than it was passively assumed.

watwat1 9y ago
Citations.

vasilipupkin 9y ago

I think blockstack is one such application: to register an identity without relying on any central party for that. Basically anything where you need to make a very small number of transactions to store information that will be cryptographically secured in a decentralized manner.