{"type":"rich","version":"1.0","author_name":"npub1g6vxlp4e0nyhs2dqxxcryztyf5f5hyuaq93nw4r87zcnv0sdsa0qqsl5wd","author_url":"https://nostr.ae/npub1g6vxlp4e0nyhs2dqxxcryztyf5f5hyuaq93nw4r87zcnv0sdsa0qqsl5wd","provider_name":"njump","provider_url":"https://nostr.ae","html":"📅 Original date posted:2017-05-23\n📝 Original message:On Mon, May 22, 2017 at 9:00 PM, Paul Sztorc \u003ctruthcoin at gmail.com\u003e wrote:\n\n\u003e I would replace \"Bitcoins you manage to steal\" with \"Bitcoins you manage\n\u003e to double-spend\". Then, it still seems the same to me.\n\u003e\n\u003e\nWith double spending, you can only get ownership of coins that you owned at\nsome point in the past.  Coins that are owned by someone else from coinbase\nto their current owners cannot be stolen by a re-org (though they can be\nmoved around).\n\nWith BMM, you can take the entire reserve.  Creating a group of double\nspenders can help increase the reward.\n\n\n\u003e\n\u003e It may destroy great value if it shakes confidence in the sidechain\n\u003e infrastructure. Thus, the value of the stolen BTC may decrease, in addition\n\u003e to the lost future tx fee revenues of the attacked chain.\n\u003e\n\u003e http://www.truthcoin.info/blog/drivechain/#drivechains-security\n\u003e\n\u003e\nThat is a fair point.  If sidechains are how Bitcoin is scaled, then\nshaking confidence in a side-chain would shake confidence in Bitcoin's\nfuture.\n\nI wasn't thinking of a direct miner 51% attack.  It is enough to assume\nthat a majority of the miners go with the highest bidder each time.\n\nIf (average fees) * (timeout) is less than the total reserves, then it is\nworth it for a 3rd party to just bid for his theft fork.  Miners don't have\nto be assumed to be coordinating, they just have to be assumed to take the\nhighest bid.\n\nAgain, I don't really think it is that different. One could interchange\n\u003e \"recent txns\" (those which could be double-spent within 2-3 weeks) with\n\u003e \"sidechain deposit tnxs\".\n\u003e\n\nIt is not \"recent txns\", it is recent txns that you (or your group) have\nthe key for.  No coordination is required to steal the entire reserve from\nthe sidechain.\n\nRecent txns and money on the sidechain have the property that they are\nriskier than money deep on the main chain.  This is the inherent point\nabout sidechains, so maybe not that big a deal.\n\nMy concern is that you could have a situation where an attack is possible\nand only need to assume that the miners are indifferent.\n\nIf the first attacker who tries it fails (say after creating a fork that is\n90% of the length required, so losing a lot of money), then it would\ndiscourage others.   If he succeeds, then it weakens sidechains as a\nconcept and that creates the incentive for miners to see that he fails.\n\nI wonder how the incentives work out.  If a group had 25% of the money on\nthe sidechain, they could try to outbid the attacker.\n\nIn fact, since the attacker, by definition, creates an illegal fork, the\neffect is that he reduces the block rate for the side chain (possibly to\nzero, if he wins every auction).  This means that there are more\ntransactions per block, if there is space, or more fees per transaction, if\nthe blocks are full.\n\nIn both cases, this pushes up the total fees per block, so he has to pay\nmore per block, weakening his attack.  This is similar to where transaction\nspam on Bitcoin is self-correcting by increasing the fees required to keep\nthe spam going.\n\nIs there a description of the actual implementation you decided to go with,\nother than the code?\n-------------- next part --------------\nAn HTML attachment was scrubbed...\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20170523/69551868/attachment.html\u003e"}