Bitcoin Forum

Ok, a pool wants one hundred confirmations before it considers the block accepted and does it's pool type stuff. I get that. what i don't get is the length of time those one hundred take to confirm. with thousands of nodes, if not millions, how are they not done in parallel? is verification time consuming and they aren't passed until the verified? Do they only forward the block to one node next for verification?

1 block doesnt take long to confirm as valid..  120 do, since generally one wouldnt expect to generate 120 blocks within a few seconds

120? i'm not sure what you are saying. afraid i'm misunderstanding something.

The blocks are a chain.  The more blocks you go down a chain the less risk there is that its an invalid fork.  So if a block has 120 confirmations, 120 blocks following it, then you can safely assume that your not paying out on an orphaned block or chain.  I think.
Sam

I assume you're referring to pools that don't pay out a block until 100/120 confirmations.  This is because blocks are unspendable for 100 confirmations by protocol, and for 120 confirmations by standard bitcoin-qt/bitcoind clients.  It means the blockchain must have at minimum 100 new blocks which build on that blockchain (thus confirming the block 100+ times) before the pool is able to spend those coins.

Since some pools do not pay orphan blocks, they generally use the 100/120 confirmation period to ensure they never accidentally pay out an orphaned block.

Ok, now it makes sense. Confirmations isn't individuals validating a single block. It s the number of blocks accepted after the block. This take time because of the 1 block per 10 minutes rule. Thanks guys!