-1

I read many articles explain the Bitcoin POW, but every article seems copy form each other. they just indicate find a nonce start from 1, but I still confused why find a nonce number is so difficult? I know the hash value must lower than the target difficulty.

for example: the Block #500000, the nonce is 1560058197, so this block hash value lower than the target when the nonce equal 1560058197.

if I start from 1 increasing the nonce to 1560058197, that is mean computer doing the SHA256 1560058197 times, that is not that hard for a pool?

1 GHash/s only need take 1 seconds? did I miss something there?

Block #500000 from Blockchain.info

  • Computing the hash is not very difficult. That's why miners are able to mine a bitcoin every 10 minutes – user93353 Jan 07 '18 at 02:52
  • 1
    Once you run out of nonces, you vary the block contents to change the block root hash and then try another 4 billion nonces. – CodesInChaos Jan 07 '18 at 19:50
  • When you say why its difficult to find the nonce, do you mean difficult to compute the number? Or do you mean some other part is difficult? – DFord Jan 08 '18 at 19:46
  • Precise answer to your question is given here - https://bitcoin.stackexchange.com/questions/52032/how-much-time-in-average-does-it-take-for-an-simple-pc-to-create-block – ArunGeorge Jan 09 '18 at 05:25
  • @ArunGeorge I think the OP's confusion is that there is only a 32-bit nonce, while it takes far more than 2^32 hash computations to match the block difficulty. – CodesInChaos Jan 09 '18 at 09:17

1 Answers1

1

before I thought it would guarantee to find a nonce when you count 1 to 2^32, but no....there is no guarantee

a friend told me, most of the time the computers run out of nonce count and usually they couldn't find a hash below the target, so they need change the block content then do that again, that's why miners need a bit of luck!