On Wed, Feb 12, 2014 at 7:12 AM, Rune Kjær Svendsen <runesv...@gmail.com> wrote: > Instead of trying to remove the possibility of transaction > malleability, would it make sense to define a new, "canonical > transaction hash/ID" (cTxID), which would be a hash of the part of the > transaction data which we know is not malleable, and have clients use > this cTxID internally, thus making the traditional transaction hash > irrelevant for a client to function correctly?
This is fine and good. But it only scratches the surface of the problems created by malleability, especially for fancier transaction protocols. Mutation allows you to invalidate a chain of unconfirmed transaction by mutating the parent. This breaks any protocol which depends on creating a precomputed nlocked time refund transaction. So a canonical ID can be used to prevent some buggy behavior it doesn't actually fix the problem. Fortunately the non-fixed parts aren't too critical today. On Wed, Feb 12, 2014 at 8:22 AM, Alan Reiner <etothe...@gmail.com> wrote: > I think the solution is simply to encourage Bitcoin software developers to > design their software to use this static ID, instead of the full transaction > hash. If MtGox had talked those IDs instead of the TX ID, their software > would've correctly identified the mutated transactions and there would be > no problem. This is incorrect. MtGox was automatically issuing replacement transactions resulting in double payments. When you attempt to replace/reissue/cancel a transaction you __MUST__ double-spend the original transaction. If the original transaction has not been conflicted then it is possible someone will pull the original transaction out of a hat and both your replacement and the original will be confirmed. It is not safe at any time to look to see if the original has been confirmed yet, and if not reissue— not because mutation may mean you're looking in the wrong place— but because the state of the world could change nano-seconds after you looked. If you do double-spend the original then there is no chance that both will go through, you'll have atomic exclusion and only one transaction or the other will be confirmed. ------------------------------------------------------------------------------ Android apps run on BlackBerry 10 Introducing the new BlackBerry 10.2.1 Runtime for Android apps. Now with support for Jelly Bean, Bluetooth, Mapview and more. Get your Android app in front of a whole new audience. Start now. http://pubads.g.doubleclick.net/gampad/clk?id=124407151&iu=/4140/ostg.clktrk _______________________________________________ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
