Truthcoin-on-BTC site: https://bitcoinhivemind.com
Quote from: evand on July 25, 2015, 08:48:44 PM1. Incorrect oracle results are also possible because of simpler attacks than p+epsilon, such as ordinary bribery, and one person / group quietly buying up half the votecoins.2. Frontrunning also has some more interesting and complex solutions involving batch market processing; see http://cdetr.io/smart-markets/ for some details and other useful implications.3. In addition to simple front running, if all share creation must pass through market orders against the AMM, you get other HFT-ish problems when two people have client-side limit orders that are being reconciled over the course of many small trades. (This assumes there's no way for two limit orders that are large compared to the liquidity parameter to meet on the blockchain.)4. There's also the freeloader market problem: can someone create a competing market that is cheaper to operate because it imports the truthcoin oracle results for market resolution without paying for them? Obviously they could do this as a centralized business, but that has a whole host of downsides. But can this be done as eg an Ethereum smart contract? (Counterpoints: will Eth work? Is that contract expensive to run on-chain? etc.) Can it be done as a separate chain, whose only goal is to be a leech?5. I'm not sure whether the whole class of problems surrounding poorly resolved vague claims counts as an attack, but I haven't seen much discussion beyond "hopefully authors will learn that's a dumb idea".6. Then there's the "unethical claims" problem: I've seen advocacy that such claims should be judged "undecidable", but I suspect the Schelling point and equilibrium behavior is to actually judge them as written. (In particular, I suspect that for any common set of norms, I as an attacker can find a claim where the question "is claim X ethical?" is a divisive question, and that I can often find such a claim where the answer to that depends on what exact event caused the claim to resolve that way.) I'm not sure how much of a problem this really is, but I've seen a lot of people assuming it would be bad. It also leads into the question of "paying for public bads".In general, it seems that blockchain-level attacks are getting good, thorough discussion, and papers written that summarize the major points. But I'm not seeing that for stuff specific to Truthcoin, which bothers me. But there's a limit when the community is this much smaller.
Quote from: evand on July 25, 2015, 08:48:44 PMIn general, it seems that blockchain-level attacks are getting good, thorough discussion, and papers written that summarize the major points. But I'm not seeing that for stuff specific to Truthcoin, which bothers me. But there's a limit when the community is this much smaller.
Quote from: evand on July 26, 2015, 03:04:27 AMre: #3, what is the expected sequence of events when one trader is willing to buy YES shares at probabilities as high as 0.51, the price is currently 0.51, a new trader arrives who is willing to buy NO shares at probabilities as low as 0.49, and their willingness to trade is large compared to the amount of liquidity the AMM will provide between those prices? Does this result in more than 2 transactions? Do those transactions leak information in such a way that someone can make informed HFT guesses about the traders intents and make money?