rich1.0Bastien TEINTURIER [ARCHIVE] (npub17f…ntr0s)https://yabu.me/npub17fjkngg0s0mfx4uhhz6n4puhflwvrhn2h5c78vdr5xda4mvqx89swntr0snjumphttps://yabu.me📅 Original date posted:2019-11-22 📝 Original message: While I agree with most of your points, I think there are subtleties to explore before completely rejecting the idea. every use of proof-of-work today (other than to power Bitcoin itself, as > Bitcoin cannot support itself) can instead be done by using Bitcoins to > impose this economic cost. > That is philosophically true, but the complexity of integrating that small PoW into Lightning is much lower than the complexity of integrating **fair, un-gameable** upfront payments. And not all PoW is born equal: there are a lot of PoW schemes that have different trade-offs than Bitcoin mining (think ASIC-resistance such as variants of Cuckoo Cycle). Another key point is that creating ASICs for this PoW is fundamentally different from creating ASICs for mining a crypto-currency. Solving this PoW doesn't earn you any money: it merely allows you to spam to temporarily disrupt the network. Since this PoW isn't used in any consensus, we can change the spam PoW algorithm anytime we want, making all previous ASICs obsolete. So it's not obvious to me that anyone would find it viable to invest in creating such ASICs. As hardware specialization for the specific Lightning-Network-proof-of-work > arises, we will find that to practically limit spam, intermediate nodes > will have to increase and increase the threshold for accepting > proof-of-work, as spammers are going to switch to the more-specialized > hardware. > That's where I think it can be more subtle than what you describe (I may be wrong though as predicting future behavior is hard). Since I'm ruling out ASICs, we're only dealing with "normal" hardware bottlenecks (cpu/ram). That means attackers are not playing at a completely different scale than normal users. The cost for attackers to generate an amount of spam mimicking N normal users will then be somewhat linear in N (to be investigated further). That's exactly the same result as upfront payments, where an attacker can still spam like he's N users if he's ready to pay a cost linear in N. I'm slightly playing devil's advocate for the PoW proposal because I think it's worth exploring more, even if we eventually abandon it. Maybe you're right and it won't be as effective to fight spam as upfront payments: but right now with the arguments I've seen on this thread, I'm not yet convinced of that. Cheers, Bastien -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.linuxfoundation.org/pipermail/lightning-dev/attachments/20191122/32cc41a8/attachment.html>