{"type":"rich","version":"1.0","author_name":"npub1j3u42vq63qzs2nyddgkf4s4t7pa85x855vas54e6yauxsvpf2wcsacwg9h","author_url":"https://nostr.ae/npub1j3u42vq63qzs2nyddgkf4s4t7pa85x855vas54e6yauxsvpf2wcsacwg9h","provider_name":"njump","provider_url":"https://nostr.ae","html":"📅 Original date posted:2016-12-11\n📝 Original message:Andrew Johnson wrote:\n\u003e \"You miss something obvious that makes this attack actually free of cost.\n\u003e Nothing will \"cost them more in transaction fees\". A miner can create\n\u003e thousands of transactions paying to himself, and not broadcast them to\n\u003e the network, but hold them and include them in the blocks he mines. The\n\u003e fees are collected by him because transactions are included in a block\n\u003e that he mined and the left amount is in another wallet of the same\n\u003e person. Repeat this continuously to fill blocks.\"\n\u003e \n\u003e This is easily detectable as long as the network isn't heavily\n\u003e partitioned(which is an assumption we make today in order for\n\u003e transaction propagation to work reliably as well as for xThin and\n\u003e CompactBlocks to work effectively to reduce block transmission time). \n\u003e Other miners would have an incentive to intentionally orphan blocks that\n\u003e contained a large number of transactions that their nodes were unaware of.\n\u003e \n\u003e I don't think this sort of attack would last long.  Even later when\n\u003e subsidies are drastically reduced, you would still lose out on\n\u003e significant genuine fee revenue if your orphan rate increased even\n\u003e 10%(one out of ten of your poison blocks intentionally orphaned by\n\u003e another miner).\n\u003e \n\nI disagree.\n\nI didn't say this is impossible to detect, but it is hard to act against\nit. One miner orphaning the block intentionally is very unlikely if that\nminer acts rationally. It would only make sense if 51% of the hash rate\nwould intentionally orphan it. Otherwise the miner who intentionally\norphans a valid block, let's say block X, has to continue to mine one in\nits place on top of block X-1, and by the time he finds one:\n\na) his block X' is rejected by other miners because they already have a\nvalid block X on top of which they already started to mine;\n\nb) block X+1 was already found and broadcasted, so the miner who\norphaned X intentionally is on the shorter chain ignored by the network.\n\nSo, one miner cannot do anything about it. Even a pool cannot do\nanything about it, because the loss is greater. You need 51% of the hash\nrate to intentionally orphan it, and all the miners forming 51% need to\nbe colluding and know for sure that every one will intentionally orphan\nthe said block, otherwise there's a huge risk of loss for who does it.\nNobody would gamble to do this (I am not sure if gambling is the right\nword, since the loss is 100% sure here). But, we are not discussing 51%\nattacks because those are a different topic.\n\n-------------- next part --------------\nA non-text attachment was scrubbed...\nName: signature.asc\nType: application/pgp-signature\nSize: 488 bytes\nDesc: OpenPGP digital signature\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20161212/952907bb/attachment.sig\u003e"}