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Speaking of a better bitcoin, why can't the proof of work aspect be something that's useful instead of a huge waste of electricity? Perhaps solving hard proble

Speaking of a better bitcoin, why can't the proof of work aspect be something that's useful instead of a huge waste of electricity? Perhaps solving hard problems like protien folding, or a big virtual CPU that people can send processes to?

DigitalJack 14y ago
Because protein folding doesn't validate transactions, and doesn't solve the "Byzantine Generals" problem.
betterunix 14y ago
How about not pouring energy into Bitcoin and just doing something more efficient: http://www.links.org/?p=1179 http://www.links.org/?p=1179 (Or maybe the Bitcoin community should just calm down, develop a rigorous definition of the security properties they want, and then develop a system that meets that definition. Right now it is all hand-wavy, vague, and it ignores a known polynomial time attack.)
kiba 14y ago
Speaking of a better bitcoin, why can't the proof of work aspect be something that's useful instead of a huge waste of electricity? It's not a huge waste of electricity. It provides security for the bitcoin ecosystem.
- betterunix 14y ago
  Only as long as nobody comes along with a tiny bit more computing power than the rest of the Bitcoin system and decides to double spend their money. Ultimately, you would need to use half of all computing power in the world for Bitcoin for it to be secure.
  - warfangle 14y ago
    Similar things have happened: look into the history of blockchain forks.
  - jacoblyles 14y ago
    PPC coin is more secure against 51% attacks, because existing holders of coin don't need large amount of computing power to generate proof-of-stake blocks. To launch a 51% attack against PPC, you need 51% of the computing power and 51% of the coin-age, coins times the amount of time that has past since they were last spent.
    - betterunix 14y ago
      Is there a better technical paper about PPCoin than the 6 page whitepaper?
jacoblyles 14y ago
There are coins with much lower mining costs, like PPC coins. It uses a "proof of stake" algorithm instead of a "proof of work". I still haven't quite wrapped my head around the math. Here is the paper: http://www.ppcoin.org/static/ppcoin-paper.pdf http://www.ppcoin.org/static/ppcoin-paper.pdf
uvdiv 14y ago
I've been looking for an answer to this question for a while -- why not build a digital commodity currency, where useful computation is a commodity? (I've yet to find a satisfying response to this). Several problems come to mind: * There's not enough computation. With BTC-type currencies, the value of the money is far higher than the cost of the backing computation (look up bitcoin mining calculations). If you have a computational commodity currency, they should be closely linked (by definition!). And a home PC can support a trivial amount of computation ($100's at most) -- not enough to be useful. * Not enough demand for (pure, parallelizable) computation. * No intrinsic way to "store" computation. You can record the existence of computation, but if this done by a distributed P2P system like bitcoin, the commodity-backing property is lost. A file verifying that a computation was performed is not itself computation: it doesn't solve any problems, it has no intrinsic value. Of course a legal private currency, backed by banks and courts, could keep track of such debts and make them enforceable. * Security problem: you would need to run arbitrary machine code on a home PC, if this were to have any useful value. This is dangerous and unsolved. Is there any way to run, e.g., untrusted CUDA code in a sandbox? (I believe no) * Accounting. There's no pure "unit" of computation: you would have many types of computational problems, being assigned to many different types of hardware. In the real world, I think you wouldn't end up with a single currency so much as a market, with many currencies and many fluctuating exchange rates. If you could extract a currency from this, it would be as a currency basket (5% protein folding, 5% linear algebra...) So I suspect this wouldn't work well today. Maybe in the future.

DigitalJack 14y ago

Because protein folding doesn't validate transactions, and doesn't solve the "Byzantine Generals" problem.

betterunix 14y ago

How about not pouring energy into Bitcoin and just doing something more efficient: http://www.links.org/?p=1179 http://www.links.org/?p=1179 (Or maybe the Bitcoin community should just calm down, develop a rigorous definition of the security properties they want, and then develop a system that meets that definition. Right now it is all hand-wavy, vague, and it ignores a known polynomial time attack.)

kiba 14y ago

Speaking of a better bitcoin, why can't the proof of work aspect be something that's useful instead of a huge waste of electricity? It's not a huge waste of electricity. It provides security for the bitcoin ecosystem.

betterunix 14y ago
Only as long as nobody comes along with a tiny bit more computing power than the rest of the Bitcoin system and decides to double spend their money. Ultimately, you would need to use half of all computing power in the world for Bitcoin for it to be secure.
- warfangle 14y ago
  Similar things have happened: look into the history of blockchain forks.
- jacoblyles 14y ago
  PPC coin is more secure against 51% attacks, because existing holders of coin don't need large amount of computing power to generate proof-of-stake blocks. To launch a 51% attack against PPC, you need 51% of the computing power and 51% of the coin-age, coins times the amount of time that has past since they were last spent.
  - betterunix 14y ago
    Is there a better technical paper about PPCoin than the 6 page whitepaper?

jacoblyles 14y ago

There are coins with much lower mining costs, like PPC coins. It uses a "proof of stake" algorithm instead of a "proof of work". I still haven't quite wrapped my head around the math. Here is the paper: http://www.ppcoin.org/static/ppcoin-paper.pdf http://www.ppcoin.org/static/ppcoin-paper.pdf

uvdiv 14y ago

I've been looking for an answer to this question for a while -- why not build a digital commodity currency, where useful computation is a commodity? (I've yet to find a satisfying response to this). Several problems come to mind: * There's not enough computation. With BTC-type currencies, the value of the money is far higher than the cost of the backing computation (look up bitcoin mining calculations). If you have a computational commodity currency, they should be closely linked (by definition!). And a home PC can support a trivial amount of computation ($100's at most) -- not enough to be useful. * Not enough demand for (pure, parallelizable) computation. * No intrinsic way to "store" computation. You can record the existence of computation, but if this done by a distributed P2P system like bitcoin, the commodity-backing property is lost. A file verifying that a computation was performed is not itself computation: it doesn't solve any problems, it has no intrinsic value. Of course a legal private currency, backed by banks and courts, could keep track of such debts and make them enforceable. * Security problem: you would need to run arbitrary machine code on a home PC, if this were to have any useful value. This is dangerous and unsolved. Is there any way to run, e.g., untrusted CUDA code in a sandbox? (I believe no) * Accounting. There's no pure "unit" of computation: you would have many types of computational problems, being assigned to many different types of hardware. In the real world, I think you wouldn't end up with a single currency so much as a market, with many currencies and many fluctuating exchange rates. If you could extract a currency from this, it would be as a currency basket (5% protein folding, 5% linear algebra...) So I suspect this wouldn't work well today. Maybe in the future.