Seriously quoting a quote who isn't even publishing his source "Somebody did a math paper on this recently". Who did this, what is his/her background and where can we find this paper?
And I'm not anti-LTC, I'm actually quite happily mining LTC with all the GPUs I nearly sold. As a miner I don't care why a coin is valuable, I mine and sell the most profitable. But as a coin user using it for actual purchases and some investments I want to know why a coin is better for me and faster confirmation times without actual, real-world benefits won't convince me...
And I'm not anti-LTC, I'm actually quite happily mining LTC with all the GPUs I nearly sold. As a miner I don't care why a coin is valuable, I mine and sell the most profitable. But as a coin user using it for actual purchases and some investments I want to know why a coin is better for me and faster confirmation times without actual, real-world benefits won't convince me...
From the reddit thread: https://bitcoil.co.il/Doublespend.pdf
Always useful to get the source: the original quoter didn't understand the paper's implication in Litecoin's specific context where some assumptions aren't valid.
The paper demonstrates that with a sizable portion of the network hashrate, only the number of confirmations matters, not the time constant (the average delay between blocks) for the confidence you can have in a transaction not being overridden by a double spend.
But... as the paper explains:
Quote
The time constant might be relevant, if we assume that the attacker cannot sustain his
hashrate for a prolonged period of time. In this case, even majority hashrate does not
guarantee success, as the attack could take more time than available. However, it does
not seem likely that an attacker would go through the trouble of obtaining enormous
computational resources and only maintain them for a time short enough to make this
consideration relevant.
hashrate for a prolonged period of time. In this case, even majority hashrate does not
guarantee success, as the attack could take more time than available. However, it does
not seem likely that an attacker would go through the trouble of obtaining enormous
computational resources and only maintain them for a time short enough to make this
consideration relevant.
The part about acquiring enormous computational resources is relative. It is is truly difficult for Bitcoin because you must acquire ASICs to be a credible threat now. It's not true for Litecoin: botnets are rent you pay them by the time spent using them and botnets are effective threats as scrypt is CPU-friendly.
So if Litecoin had used sha256d its faster blocks could have been an advantage because botnets at best have access to GPUs, not FPGAs and ASICs, but as a CPU-friendly hash is used, botnets becomes the obvious choice for people shady enough to try double spends. In this particular context attacks' costs are proportional to the time constant and the whole argument falls down: a short one is indeed less secure.
There is another problem: block propagation. Assuming Litecoin didn't change Bitcoin block size settings with 2.5 minutes blocks you need 4 times the bandwidth needed by Bitcoin (it could be solved by restricting block size to 1/4th of Bitcoind blocks, but this is a protocol hard fork). Satoshi is believed to have chosen these values so that the lowest network bandwidths would still be able to use Bitcoin.
