From o.thyfronitis at ed.ac.uk Tue Nov 26 11:41:50 2019 From: o.thyfronitis at ed.ac.uk (Orfeas Stefanos Thyfronitis Litos) Date: Tue, 26 Nov 2019 11:41:50 +0000 Subject: [Lightning-dev] A proposal for up-front payments. In-Reply-To: <3G9Jh5pNv8G2TfPVvv1HVWiCyyd735xvguy3SegPw-_Nxx11gxNJ4WezrNZ37SOIhsSUi_6wG6GR9PnBC93eBwihJFDZQcqJFt1k24RjZ-I=@protonmail.com> References: <87ftj33w2z.fsf@rustcorp.com.au> <875zjvum7n.fsf@rustcorp.com.au> <20191108123236.kmi4dyqyix2hztyo@erisian.com.au> <87pnhzqpg3.fsf@rustcorp.com.au> <3G9Jh5pNv8G2TfPVvv1HVWiCyyd735xvguy3SegPw-_Nxx11gxNJ4WezrNZ37SOIhsSUi_6wG6GR9PnBC93eBwihJFDZQcqJFt1k24RjZ-I=@protonmail.com> Message-ID: Hello ZmnSCPxj, > This can be made "the same" by any of the following methods: > > * Burning the up-front fees. This would impose a hard maximum of 21 * 10^6 * 10^8 global lifetime hops, and a much lower practical one. PoW OTOH doesn't impose such limits. Hence different dynamics. > * Locking the up-front fees for a time, then reverting them to the original sender. This means that I can burst-spam today, wait until unlock, repeat. If the PoW scheme somehow enforces fresh PoWs (e.g. by needing (nonce || recent block hash) as proof), I can't do this attack. > Fees and PoW are equivalent. If by "equivalent" you mean "a drop-in replacement", then I hope the subtle differences above and the previous discussion show that this is not the case. If by "equivalent" you mean (a formal version of) "for any scheme that uses PoWs, there exists a fee-based scheme with the same incentives and large-scale dynamics", then that's a very strong claim of which I would love to see a proof (and a formal statement). This is not to say that I believe PoWs are the solution to spam, just that they warrant separate investigation from fees. Best, Orfeas -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.