On Wednesday, October 21, 2015 8:31:42 AM Christian Decker wrote: > On Wed, Oct 21, 2015 at 9:52 AM Luke Dashjr <[email protected]> wrote: > > On Wednesday, October 21, 2015 7:39:45 AM Christian Decker wrote: > > > On Wed, Oct 21, 2015 at 8:19 AM Luke Dashjr <[email protected]> wrote: > > > > This doesn't completely close malleability (which should be > > > > documented > > > > in > > > > > > the BIP), so I'm not sure it's worth the cost, especially if closing > > > > malleability later on would need more. How about specifying flags > > > > upfront > > > > > > in the UTXO-creating transaction specifying which parts the signature > > > > will cover? This would allow implementation of fully > > > > malleability-proof wallets. > > > > > > As far as I see it the only remaining venues for malleability are the > > > use of sighash flags that are not SIGHASH_ALL, as mentioned in the > > > BIP. Any > > > > use > > > > > of non-sighash_all flags is already an explicit permission to modify > > > the transactions, by adding and removing inputs and outputs, so I > > > don't see > > > > how > > > > > these can be made non-malleable. Am I missing something? > > > > Signer malleability is still a notable concern needing consideration. > > Ideally, > > wallets should be trying to actively CoinJoin, bump fees on, etc any > > pending > > transactions in the background. These forms of malleability affect nearly > > as > > many real use cases as third-party malleability. > > > > Luke > > How is signer malleability still a problem if we remove the signatures from > the transaction ID of the transaction and all preceding transactions? The > signer can re-sign a transaction but it won't change the transaction ID.
The signer can also change the order of the inputs, the inputs themselves, add/remove outputs, etc... all which should be possible without becoming a different logical transaction. The only unique property of the logical transaction is the scriptPubKey/address. Luke _______________________________________________ bitcoin-dev mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
