6 ms·

There's no evidence Proof-of-Stake can work as a replacement for Proof-of-Work.

derefr 9y ago
No, not yet. Bitcoin's "Lightning Network" is going to happen, though, so we'll see proof one way or the other soon enough.
- JohnJamesRambo 9y ago
  How are you so certain LN will ever be implemented? I'm more confident Vitalik could get PoS working before LN ever gets here. LN is vaporware and was supposed to be here long ago, yet here we are.
  - anonyx69 9y ago
    Agree, but a game like crypo kitties is probably the best and only tolerable use case for LN.
  - ChrisClark 9y ago
    I'm actually very surprised at how slow the LN dev is going. There is actually a working version of Raiden (full, not just µRaiden) on an ethereum testnet, I'm really not sure why LN on bitcoin is going so slowly.
    - em3rgent0rdr 9y ago
      Move fast and break things is probably not a good idea for money.
      - derefr 9y ago
        By analogy to driverless cars, it'd make sense to avoid letting your car out on public roads; but it wouldn't make sense to avoid building a prototype and running it around a test track. A real thing lends itself to iteration much better than an on-paper idea does.
      - tree_of_item 9y ago
        In that case Ethereum shouldn't exist at all. Solidity and the EVM itself are a good example of that philosophy. If they weren't gonna move fast they should have waited until they had a better story for static analysis and model checking of smart contracts.
        em3rgent0rdr 9y ago
        Not necessarily. Keep in mind when Ethereum started, it had no value. But with bitcoin, there is huge value and so potentiality for people to loose a lot of money if there was one minor bug.
    - jcoffland 9y ago
      Because LN is flawed as an idea. Who wants to lock in their Bitcoin to a LN channel to pay only one entity on the other end repeatedly? It doesn't make any sense. If, and that's a huge if, you got a lot of people to lock their money up in various interconnected LN channels how do you route money through these channels in a way that is fast and inexpensive? No one has answered that question definitively. LN proponents have put LN forward as this magical scaling solution were you can effortlessly transact Bitcoin off-chain both cheaply and inexpensively. The nontechnical believers have lapped it up not knowing that LN is an incomplete idea that starts with locking your coin up in one or more channels and end with some magical and as of yet undiscovered distributed routing network that finds a path through existing channels from channels you've already committed to, to channels your payee has committed to. That such a path exists, is cost effective and is reliable, in that your coins don't get stuck somewhere along the way, is an open question. In short, LN is half baked at best.
    - em3rgent0rdr 9y ago
      LN shows some very good progress in their latest video uploaded today: https://www.youtube.com/watch?v=a73Gz3Tvx3k https://www.youtube.com/watch?v=a73Gz3Tvx3k "In this video Laolu (co-founder of Lightning Labs) demonstrates a multi-hop payment on Bitcoin's mainnet which travels across the 3 major Lightning implementations. In the demo Laolu (a.k.a roasbeef) sends a payment from our Lightning desktop app (https://github.com/lightninglabs/ligh... https://github.com/lightninglabs/ligh...) to Starblocks, a coffee payment demo." "This payment marks the first multi-hop, cross-implementation payment on Bitcoin's mainnet. All transaction performed in the video were performed completely off-chain, instantly, and with virtually zero fees. Lightning allows instant, low-fee payments on Bitcoin, enabling the system to scale further for the next wave of adoption. Additionally, Lightning unlocks a new class of use cases for Bitcoin enabled by the ability to instantly send low-fee payments on the system."
  - vertex-four 9y ago
    Lightning Network unfortunately depended on transaction malleability being fixed. This was, I believe, fixed by segwit. So it's only been a possibility since August - and the Lightning Network Daemon has been under heavy development. It can now run on the Bitcoin network itself, but is not yet in a state where it works "automagically", nor would many people depend on the code being relatively bug-free yet.
  - SkyMarshal 9y ago
    LN testnets are up and running, transactions work, and there's a cross-platform desktop app in beta. It's almost here, will likely go into production sometime in 2018.
- kristofferR 9y ago
  Proof of stake and Lightning Network have nothing to do with each other, they're on completely separate axis.
- nrhk 9y ago
  I could be wrong but the Lightning Network is hardly a proof of stake system, just used to open up state channels between two members for lots of off chain transactions before finalizing on the main chain.
  - deleted 9y ago
    [deleted]
drcode 9y ago
I'd be happy respond to this comment if it was a bit more fleshed out and didn't sound like an attempt at trolling, for instance why you don't consider existing POS currencies like NXT to be "evidence".
- meebs 9y ago
  For those of us still ignorant -- can you point to a resource where I can learn about these differences and evidence?
- xorcist 9y ago
  Because those all require a trusted third party to make regular checkpoints of the blockchain. The argument is not that it is impossible but that no one has been able to design it trustless. It is a reasonable argument and while you may not agree with the desire to avoid trusted third parties but there's no reason to dismiss it as trolling.
  - drcode 9y ago
    Well, the precise criticism you're making is a bit unclear to me but I'll try to respond: Modern proof of stake systems have a concept of "finality" which I think is what you're referring to when you say "checkpoint" (older POS systems also had a more traditional checkpoint concept, but I assuming you're arguing against modern implementations) In order to determine whether a block has "finality" in a POS system you need to either (A) have a computer running regularly on the network to determine finality on your own or (B) trust a third party to give you a valid finality designator. So it is true that you have to trust a third party with these systems if (1) you haven't connected to the network for a year or so or (2) you are launching a brand new node. Of course, with bitcoin #2 is also an issue since there's no way you can install bitcoin software on a new node without getting it from a trusted party.
    - xorcist 9y ago
      I have never heard of "finality" being used outside Ethereum, but maybe you can point me at which existing PoS systems use the term? Or is it Ethereum specifically which is the modern PoS system? The Ethereum PoS system, which is still a prototype and may change before the final version, uses checkpoints to guard against chain re-orgs. It is not trustless in the same sense as the Ethash system is. It's not exactly a secret but a calculated tradeoff. The question here however was about how "currencies like NXT" work, which can hardly be described as modern seeing it was one of the first together with PPC. I believe they never fixed the fact that the optimum mining strategy is not the altruistic one the reference client uses. As long as all participants use the reference client they're safe, but it's not something you would want to base a trillion dollar economy on. In general the challenges with proof-of-stake systems are how to avoid collusion, how to avoid exploratory mining on every possible chain, and variants thereof. (There's also the related problem how to bootstrap a node from scratch in face of equally probable views of history.) Different blockchains have tried different ways to mitigate this, including hard coded re-org limits and coin weights, but the only ones that have proven at scale are the ones that regularly checkpoint the chain. But please correct me if you know of any exceptions.
Jd 9y ago
There was also no evidence you could do sub one minute blocks for Proof-of-Work. Then Vitalik read the ghost paper and figured it out. Put enough very smart people working on hard problems and eventually they will figure some of them out.
- etr-strike 9y ago
  Of course you can do sub one minute blocks. Bitcoin chose 10 minute blocks to maximize decentralization. Bitcoin could also do 12 second blocks, but then the network would be as centralized as Ethereum.
  - aqme28 9y ago
    How does block time affect centralization? I understand that more storage is a centralization pressure, but how does blocktime relate assuming the same number of transactions?
    - etr-strike 9y ago
      Because mining is dependent on the rate at which information can propagate across the network. If a mining pool is able to hear about the next block 1s sooner than another pool, it has a significant advantage when blocks only take 12s to mine. If blocks take 10min to mine, that 1s is less of an advantage.
      - DennisP 9y ago
        If miners get paid for valid blocks that don't end up included in the chain, that also makes the 1s less of an advantage. Hence GHOST. Here's the original paper [1] and a later one [2]. [1] https://www.semanticscholar.org/paper/Accelerating-Bitcoin-s-Transaction-Processing-Fast-Sompolinsky-Zohar/401680ef12c04c247c50737b9114c169c660aab9 https://www.semanticscholar.org/paper/Accelerating-Bitcoin-s... [2] https://eprint.iacr.org/2016/545.pdf https://eprint.iacr.org/2016/545.pdf
        9y ago
sciyoshi 9y ago
There's been a number of attempts at least, see Ouroboros: https://eprint.iacr.org/2016/889.pdf https://eprint.iacr.org/2016/889.pdf I'm still on the fence about the viability of PoS from the perspective that PoW at least means you have a chance of reward from using mining hardware that you probably already own, whereas PoS increases that barrier of adoption.

No, not yet. Bitcoin's "Lightning Network" is going to happen, though, so we'll see proof one way or the other soon enough.

JohnJamesRambo 9y ago
How are you so certain LN will ever be implemented? I'm more confident Vitalik could get PoS working before LN ever gets here. LN is vaporware and was supposed to be here long ago, yet here we are.
- anonyx69 9y ago
  Agree, but a game like crypo kitties is probably the best and only tolerable use case for LN.
- ChrisClark 9y ago
  I'm actually very surprised at how slow the LN dev is going. There is actually a working version of Raiden (full, not just µRaiden) on an ethereum testnet, I'm really not sure why LN on bitcoin is going so slowly.
  - em3rgent0rdr 9y ago
    Move fast and break things is probably not a good idea for money.
    - derefr 9y ago
      By analogy to driverless cars, it'd make sense to avoid letting your car out on public roads; but it wouldn't make sense to avoid building a prototype and running it around a test track. A real thing lends itself to iteration much better than an on-paper idea does.
    - tree_of_item 9y ago
      In that case Ethereum shouldn't exist at all. Solidity and the EVM itself are a good example of that philosophy. If they weren't gonna move fast they should have waited until they had a better story for static analysis and model checking of smart contracts.
      - em3rgent0rdr 9y ago
        Not necessarily. Keep in mind when Ethereum started, it had no value. But with bitcoin, there is huge value and so potentiality for people to loose a lot of money if there was one minor bug.
  - jcoffland 9y ago
    Because LN is flawed as an idea. Who wants to lock in their Bitcoin to a LN channel to pay only one entity on the other end repeatedly? It doesn't make any sense. If, and that's a huge if, you got a lot of people to lock their money up in various interconnected LN channels how do you route money through these channels in a way that is fast and inexpensive? No one has answered that question definitively. LN proponents have put LN forward as this magical scaling solution were you can effortlessly transact Bitcoin off-chain both cheaply and inexpensively. The nontechnical believers have lapped it up not knowing that LN is an incomplete idea that starts with locking your coin up in one or more channels and end with some magical and as of yet undiscovered distributed routing network that finds a path through existing channels from channels you've already committed to, to channels your payee has committed to. That such a path exists, is cost effective and is reliable, in that your coins don't get stuck somewhere along the way, is an open question. In short, LN is half baked at best.
  - em3rgent0rdr 9y ago
    LN shows some very good progress in their latest video uploaded today: https://www.youtube.com/watch?v=a73Gz3Tvx3k https://www.youtube.com/watch?v=a73Gz3Tvx3k "In this video Laolu (co-founder of Lightning Labs) demonstrates a multi-hop payment on Bitcoin's mainnet which travels across the 3 major Lightning implementations. In the demo Laolu (a.k.a roasbeef) sends a payment from our Lightning desktop app (https://github.com/lightninglabs/ligh... https://github.com/lightninglabs/ligh...) to Starblocks, a coffee payment demo." "This payment marks the first multi-hop, cross-implementation payment on Bitcoin's mainnet. All transaction performed in the video were performed completely off-chain, instantly, and with virtually zero fees. Lightning allows instant, low-fee payments on Bitcoin, enabling the system to scale further for the next wave of adoption. Additionally, Lightning unlocks a new class of use cases for Bitcoin enabled by the ability to instantly send low-fee payments on the system."
- vertex-four 9y ago
  Lightning Network unfortunately depended on transaction malleability being fixed. This was, I believe, fixed by segwit. So it's only been a possibility since August - and the Lightning Network Daemon has been under heavy development. It can now run on the Bitcoin network itself, but is not yet in a state where it works "automagically", nor would many people depend on the code being relatively bug-free yet.
- SkyMarshal 9y ago
  LN testnets are up and running, transactions work, and there's a cross-platform desktop app in beta. It's almost here, will likely go into production sometime in 2018.
kristofferR 9y ago
Proof of stake and Lightning Network have nothing to do with each other, they're on completely separate axis.
nrhk 9y ago
I could be wrong but the Lightning Network is hardly a proof of stake system, just used to open up state channels between two members for lots of off chain transactions before finalizing on the main chain.
- deleted 9y ago
  [deleted]

drcode 9y ago

I'd be happy respond to this comment if it was a bit more fleshed out and didn't sound like an attempt at trolling, for instance why you don't consider existing POS currencies like NXT to be "evidence".

meebs 9y ago
For those of us still ignorant -- can you point to a resource where I can learn about these differences and evidence?
xorcist 9y ago
Because those all require a trusted third party to make regular checkpoints of the blockchain. The argument is not that it is impossible but that no one has been able to design it trustless. It is a reasonable argument and while you may not agree with the desire to avoid trusted third parties but there's no reason to dismiss it as trolling.
- drcode 9y ago
  Well, the precise criticism you're making is a bit unclear to me but I'll try to respond: Modern proof of stake systems have a concept of "finality" which I think is what you're referring to when you say "checkpoint" (older POS systems also had a more traditional checkpoint concept, but I assuming you're arguing against modern implementations) In order to determine whether a block has "finality" in a POS system you need to either (A) have a computer running regularly on the network to determine finality on your own or (B) trust a third party to give you a valid finality designator. So it is true that you have to trust a third party with these systems if (1) you haven't connected to the network for a year or so or (2) you are launching a brand new node. Of course, with bitcoin #2 is also an issue since there's no way you can install bitcoin software on a new node without getting it from a trusted party.
  - xorcist 9y ago
    I have never heard of "finality" being used outside Ethereum, but maybe you can point me at which existing PoS systems use the term? Or is it Ethereum specifically which is the modern PoS system? The Ethereum PoS system, which is still a prototype and may change before the final version, uses checkpoints to guard against chain re-orgs. It is not trustless in the same sense as the Ethash system is. It's not exactly a secret but a calculated tradeoff. The question here however was about how "currencies like NXT" work, which can hardly be described as modern seeing it was one of the first together with PPC. I believe they never fixed the fact that the optimum mining strategy is not the altruistic one the reference client uses. As long as all participants use the reference client they're safe, but it's not something you would want to base a trillion dollar economy on. In general the challenges with proof-of-stake systems are how to avoid collusion, how to avoid exploratory mining on every possible chain, and variants thereof. (There's also the related problem how to bootstrap a node from scratch in face of equally probable views of history.) Different blockchains have tried different ways to mitigate this, including hard coded re-org limits and coin weights, but the only ones that have proven at scale are the ones that regularly checkpoint the chain. But please correct me if you know of any exceptions.

Jd 9y ago

There was also no evidence you could do sub one minute blocks for Proof-of-Work. Then Vitalik read the ghost paper and figured it out. Put enough very smart people working on hard problems and eventually they will figure some of them out.

etr-strike 9y ago
Of course you can do sub one minute blocks. Bitcoin chose 10 minute blocks to maximize decentralization. Bitcoin could also do 12 second blocks, but then the network would be as centralized as Ethereum.
- aqme28 9y ago
  How does block time affect centralization? I understand that more storage is a centralization pressure, but how does blocktime relate assuming the same number of transactions?
  - etr-strike 9y ago
    Because mining is dependent on the rate at which information can propagate across the network. If a mining pool is able to hear about the next block 1s sooner than another pool, it has a significant advantage when blocks only take 12s to mine. If blocks take 10min to mine, that 1s is less of an advantage.
    - DennisP 9y ago
      If miners get paid for valid blocks that don't end up included in the chain, that also makes the 1s less of an advantage. Hence GHOST. Here's the original paper [1] and a later one [2]. [1] https://www.semanticscholar.org/paper/Accelerating-Bitcoin-s-Transaction-Processing-Fast-Sompolinsky-Zohar/401680ef12c04c247c50737b9114c169c660aab9 https://www.semanticscholar.org/paper/Accelerating-Bitcoin-s... [2] https://eprint.iacr.org/2016/545.pdf https://eprint.iacr.org/2016/545.pdf
      - 9y ago

sciyoshi 9y ago

There's been a number of attempts at least, see Ouroboros: https://eprint.iacr.org/2016/889.pdf https://eprint.iacr.org/2016/889.pdf I'm still on the fence about the viability of PoS from the perspective that PoW at least means you have a chance of reward from using mining hardware that you probably already own, whereas PoS increases that barrier of adoption.