3 ms·

They are doing a make-work exercise which only needs to be time consuming, in order to prevent cheaters. It's mostly throw-away work. The actual computation tha

They are doing a make-work exercise which only needs to be time consuming, in order to prevent cheaters. It's mostly throw-away work. The actual computation that needs to happen is pretty trivial. I think it would be possible to fix Bitcoin so that "proof of work" is something that doesn't consume all that electricity, but I'm not sure what it would be.

mayank 14y ago
If it doesn't consume electricity at a high rate, it's not proof of work, ie there's nothing to "fix".
- wmf 14y ago
  Since it's memory-intensive, scrypt might be a more energy-efficient form of proof of work than SHA.
  - Freaky 14y ago
    Already being used: http://litecoin.org/ http://litecoin.org/ Only more efficient in that nobody's throwing lots of chunky GPUs at it.
    - wmf 14y ago
      Does a GPU use less power while mining Litecoin? It seems like the cores would be 99% idle.
      - corysama 14y ago
        Nope. The GPUs get plenty hot. The difference is that with Litecoin, your CPU gets hot too! I have not dug into the technical details, but at a glance it looks as if Litecoin motivated research that fairly successfully overcame the GPU-unfriendliness of Scrypt. If anyone here can confirm or deny this, I'd love to hear it.
        1SaltwaterC 14y ago
        The CPU doesn't get that hot. On a machine with an Athlon II 240e cgminer uses ~18% CPU vs the GPU that sits at 99% load. scrypt is indeed viable on GPUs, but it depends onto the available memory bandwidth which presumably lessens the impact of FPGA/ASIC if people start to push those as LTC mining solutions.
  - codeulike 14y ago
    which is what Litecoin tries to do, I think, but for different reasons. https://en.bitcoin.it/wiki/Litecoin https://en.bitcoin.it/wiki/Litecoin
kzrdude 14y ago
If somebody could explain what the new thing Ripple means by resolving things by consensus instead of proof-of-work, maybe that would work. But as far as bitcon presents it, proof of work is needed to resolve the problem of keeping a honest transaction log in an untrusted environment.
- tlrobinson 14y ago
  As I understand it, Ripple's trust system works by selecting multiple third-parties that are unlikely to collude against you, and checking that they agree on a transaction before considering it "confirmed". https://ripple.com/wiki/Consensus https://ripple.com/wiki/Consensus
codeulike 14y ago
I understand that its a make-work exercise, I was querying whether the output is just mined coins, or whether the output also includes verifying everyone elses transactions. My current understanding is that its the latter.
- paulhodge 14y ago
  Sure, so I'm not sure which "output" you mean. The output of the computationally-intensive part is really just a magic number that solves a puzzle. Once a miner finds that magic number, they publish a block that has the most recent transactions (which are all verified separately), as well as the special transaction where the miner grants themselves the current mining reward. Other miners see it and verify that all that stuff was correctly computed. So that whole block (which is maybe what you're calling the "output"), does contain the puzzle solution as well as all the latest transactions. But the actual specifics of the puzzle (which is currently brute-force SHA1 reversing), aren't super important. It could always be swapped out for some other task.
  - codeulike 14y ago
    By 'output' I (think) I meant the output we get for the energy used by the miners. You seem to be saying that The Miners have to verify transactions to claim their reward? When you say "which are all verified separately" - you mean verified by the same miner who publishes the block? If so then the bitcoin network as a whole benefits from their energy use. On the other hand, I see your point that the make-work is not intrinsically linked to transaction verification. But my understanding is, its the difficulty of the make-work that protects the block-chain from being hijacked by ..er... 'the bad guys', whomever they may be. So, the whole thing kinda makes sense, and the 'make-work' is like an energy commitment that keeps the whole thing integrated. The assumption being, the total commitment of all bitcoin users will always be greater than the commitment of any single attacker/attacker group.

mayank 14y ago

If it doesn't consume electricity at a high rate, it's not proof of work, ie there's nothing to "fix".

wmf 14y ago
Since it's memory-intensive, scrypt might be a more energy-efficient form of proof of work than SHA.
- Freaky 14y ago
  Already being used: http://litecoin.org/ http://litecoin.org/ Only more efficient in that nobody's throwing lots of chunky GPUs at it.
  - wmf 14y ago
    Does a GPU use less power while mining Litecoin? It seems like the cores would be 99% idle.
    - corysama 14y ago
      Nope. The GPUs get plenty hot. The difference is that with Litecoin, your CPU gets hot too! I have not dug into the technical details, but at a glance it looks as if Litecoin motivated research that fairly successfully overcame the GPU-unfriendliness of Scrypt. If anyone here can confirm or deny this, I'd love to hear it.
      - 1SaltwaterC 14y ago
        The CPU doesn't get that hot. On a machine with an Athlon II 240e cgminer uses ~18% CPU vs the GPU that sits at 99% load. scrypt is indeed viable on GPUs, but it depends onto the available memory bandwidth which presumably lessens the impact of FPGA/ASIC if people start to push those as LTC mining solutions.
- codeulike 14y ago
  which is what Litecoin tries to do, I think, but for different reasons. https://en.bitcoin.it/wiki/Litecoin https://en.bitcoin.it/wiki/Litecoin

kzrdude 14y ago

If somebody could explain what the new thing Ripple means by resolving things by consensus instead of proof-of-work, maybe that would work. But as far as bitcon presents it, proof of work is needed to resolve the problem of keeping a honest transaction log in an untrusted environment.

tlrobinson 14y ago
As I understand it, Ripple's trust system works by selecting multiple third-parties that are unlikely to collude against you, and checking that they agree on a transaction before considering it "confirmed". https://ripple.com/wiki/Consensus https://ripple.com/wiki/Consensus

codeulike 14y ago

I understand that its a make-work exercise, I was querying whether the output is just mined coins, or whether the output also includes verifying everyone elses transactions. My current understanding is that its the latter.

paulhodge 14y ago
Sure, so I'm not sure which "output" you mean. The output of the computationally-intensive part is really just a magic number that solves a puzzle. Once a miner finds that magic number, they publish a block that has the most recent transactions (which are all verified separately), as well as the special transaction where the miner grants themselves the current mining reward. Other miners see it and verify that all that stuff was correctly computed. So that whole block (which is maybe what you're calling the "output"), does contain the puzzle solution as well as all the latest transactions. But the actual specifics of the puzzle (which is currently brute-force SHA1 reversing), aren't super important. It could always be swapped out for some other task.
- codeulike 14y ago
  By 'output' I (think) I meant the output we get for the energy used by the miners. You seem to be saying that The Miners have to verify transactions to claim their reward? When you say "which are all verified separately" - you mean verified by the same miner who publishes the block? If so then the bitcoin network as a whole benefits from their energy use. On the other hand, I see your point that the make-work is not intrinsically linked to transaction verification. But my understanding is, its the difficulty of the make-work that protects the block-chain from being hijacked by ..er... 'the bad guys', whomever they may be. So, the whole thing kinda makes sense, and the 'make-work' is like an energy commitment that keeps the whole thing integrated. The assumption being, the total commitment of all bitcoin users will always be greater than the commitment of any single attacker/attacker group.