3 ms·

Wrong: All else being identical, a currency with 10 minute blocks will have a 10x mining difficulty than a currency with a 1 minute block. Lower mining difficu

by drcode 13y ago

Wrong: All else being identical, a currency with 10 minute blocks will have a 10x mining difficulty than a currency with a 1 minute block. Lower mining difficulty = Easier to beat network. (Easier to beat PER BLOCK, no difference PER UNIT TIME)

deleted 13y ago
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tlrobinson 13y ago
In fact, if you take into account the time it takes to propagate a block across the network, shorter confirmation times may actually lead to less security. e.x. if the confirmation time is 60 seconds, and it takes 30 seconds to propagate a block across the network, the miner that just mined a block will have a huge advantage in computing the next block.
- drcode 13y ago
  Well, if we start getting pedantic :-) smaller blocks also mean more block headers, which also hampers performance. On the flip side, I don't think mined blocks typically take more than five seconds, due to the efficiency of the highly-branching network (though I haven't looked at the numbers to confirm this...) But I admit I hadn't thought about that extra detail, thank for pointing it out.
makomk 13y ago
That's not true, there's a very big difference per unit time. The difficulty of attempting a double spend decreases linearly with the nominal length of the blocks, but it increases exponentially with the number of blocks required to confirm a transaction. So if for instance you decide you need an average confirmation time of 20 minutes, that'd be 2 blocks in Bitcoin and around 20 blocks in our hypothetical 1-minute Bitcoin. In general, for any given target confirmation time the 1-minute Bitcoin will be harder to attack than the 10-minute one - and this is especially true for the sub-10-minute and sub-20-minute confirmation times many merchants want. If you're targetting an average confirmation time of say 5 minutes, that's a solid 5 confirmations with 1-minute-coin but a risky zero confirmation transaction with Bitcoin - and in practice a lot of services do accept transactions with zero confirmations because it's the only way to get the level of convenience their customers expect.

by drcode 13y ago

deleted 13y ago

[deleted]

tlrobinson 13y ago

In fact, if you take into account the time it takes to propagate a block across the network, shorter confirmation times may actually lead to less security. e.x. if the confirmation time is 60 seconds, and it takes 30 seconds to propagate a block across the network, the miner that just mined a block will have a huge advantage in computing the next block.

drcode 13y ago
Well, if we start getting pedantic :-) smaller blocks also mean more block headers, which also hampers performance. On the flip side, I don't think mined blocks typically take more than five seconds, due to the efficiency of the highly-branching network (though I haven't looked at the numbers to confirm this...) But I admit I hadn't thought about that extra detail, thank for pointing it out.

makomk 13y ago

That's not true, there's a very big difference per unit time. The difficulty of attempting a double spend decreases linearly with the nominal length of the blocks, but it increases exponentially with the number of blocks required to confirm a transaction. So if for instance you decide you need an average confirmation time of 20 minutes, that'd be 2 blocks in Bitcoin and around 20 blocks in our hypothetical 1-minute Bitcoin. In general, for any given target confirmation time the 1-minute Bitcoin will be harder to attack than the 10-minute one - and this is especially true for the sub-10-minute and sub-20-minute confirmation times many merchants want. If you're targetting an average confirmation time of say 5 minutes, that's a solid 5 confirmations with 1-minute-coin but a risky zero confirmation transaction with Bitcoin - and in practice a lot of services do accept transactions with zero confirmations because it's the only way to get the level of convenience their customers expect.