Topic: What is all this computing power used for? (Read 2741 times)

In my opinion, if you can secure Bitcoin, and do something useful, like finding prime numbers, but maybe more useful Perhaps a proof of work system could be established in a future coin, based off of protein folding.

Even if other things can't be done, just finding prime numbers isn't exactly useless. Maybe there are similar things that can be found. Bitcoin can be altered by consensus--a necessary survival feature--so it's not as though this fact is really a knock against the continued use of Bitcoin. When you need to adjust the difficulty, just give multiple problems. Primecoin manages, but primecoin is silly because Bitcoin could obsolete it easily if it chose. We could even choose which kind of problem we want to solve (if the network scales difficulty to be the same) when we mine, if other alternatives exist.

I think people are overrreacting to the OP as a knee-jerk reaction to defend Bitcoin, when really that's not necessary. Bitcoin is the best option for a money system, but it's not perfect and can always improve.

Thanks D&T

I understood the good enough concept but I never worked it in to the metaphor. I think that's a good way of explaining difficult and scale w/r/t new people competing to make the guess.

That is a good simplification.  I would change "correct" to "good enough" as correct implies there is only one possible solution.  For any given block there is a nearly infinite possible solutions.  Miners are collectively just looking for the first one which is "good enough".   We measure good enough by the target, which is a 256 bit number directly proportional to difficulty.  The miner constructs a valid block, hashes it and checks to see if it is "good enough" that is the resulting hash is smaller than the target.

Right down the target is: 000000000000001CDC2000000000000000000000000000000000000000000000.  There are ~2x10^60 hashes smaller than this value and any will meet the block difficulty requirements.

How much have you thought about it because it not a trivial problem.

A proof of work must have the following characteristics:
a) have an adjustable "difficulty" which works under a very large range (bitcoin difficulty is ~150,000,000x higher today than at genesis and likely will go another 10x to 100x over next year).

b) be very fast to verify (<100ms).   Bitcoin has 52K blocks per year so someon bootstrapping 10 years after genesis woould need to validate 520K blocks in a timely manner.

c) the input of the proof must be linked to a prior proof to prevent precomputation (Bitcoin uses the prior block hash as input for current block hash to prevent solving "future" blocks).

d) the proof should be relatively compact (Bitcoin uses a 32 byte hash)

e) the solution should be probabilistic.  This means that given two competitors and one has 10x the computing power the smaller competitor should find ~9% of the solutions.  Many problems are not probablistic such that the faster competitor will always arrive at a solution first.  That would be bad from a security standpoint.

f) require no outside "trusted" source or central authority for issuing or assigning work.

h) have a mechanism to prevent  duplicated work across the network without any communication to a peer or outside data source.

Most simplistic "answers" fail this test.   For example using folding@home would work as a proof of work as long as you are willing to have the administrators of folding@home be the central bank with complete control and authority over the currency.

Use this metaphor:

Every computer participating in mining is a type of digital accountant. Every accountant is competing for the privilege of writing a page in a universal ledger everyone can read and check for errors. If an account guesses a correct number and records a page in the ledger they are awarded a sum of bitcoin.

This has been the best way of explaining mining to folks that I have encountered.

The guessing game being played is the correct header for the next block, I believe, but someone could probably correct that for me.

Do you have any examples, or are you just making stuff up because you like the way it sounds?

I think there probably are practical problems besides just finding prime numbers that could be solved for the purpose of Bitcoin. There's no reason not to switch to that. It's probably just not a priority right now.

Nice answer, gave a lot more intel than the previous one. Cheers mate :-)

Good suggestion, especially now that winter is coming 

Love it - nicely put.

It is used to heat up cold homes.

The computing power is used to increase the amount of work an attacker would need to expend in order to disrupt the network.

"Useless" computations are better for this, because it means any computations an attacker performs which are not sufficient to achieve the effect they want truly are wasted, making failed attacks very expensive.

If you don't mind, could you explain what you mean by this?  I'm not sure that you and I are representing the same concept when using the words "create all the coins".

Ok then

1)Computing power is NOT used to create bitcoins. You can create all the coins even with a single Pentium 1

2)The algorithm is open source and known, it is just sha256 hashing 

I think this is the best answer you can give him.

I'm pretty sure there hasn't been currency made from wood pulp paper in any country since at least the 19th century. Even wartime emergency money (Notgeld) wasn't printed on wood pulp paper.

Trees?

I didn't think any currency was printed on paper made from trees.

I'm pretty sure that U.S. currency is 75% cotton and 25% linen

Those prime numbers primecoin is searching for have absolutely no scientific value. The problem is you need a very specific "cryptographic puzzle" to do what the bitcoin puzzle does, one that's difficult to solve but very easy to verify. Protein folding and such "useful" problems are almost never of such type.

If you kill trees and print up fancy toilet paper with heads of dead presidents then it's not "going up in smoke" but God forbid you let your Bitcoin miner run, the environment yo!