В Thu, 14 May 2020 07:31:13 +0200 Ruben Somsen <[email protected]> wrote:
> Hi Dmitry, > > >While refund_tx_1 is in the mempool, Bob gives success_tx to the > >friendly miner > > I see, so you're talking about prior to protocol completion, right > after Alice sends Bob the success_tx. The reason this is not an issue > is because Alice and Bob both had to misbehave in order for this to > happen. Bob is misbehaving here because he should have published the > success_tx before refund_tx_1 became valid, and Alice is misbehaving > here because she should have sent the revoke_tx (which invalidates > the success_tx) followed by refund_tx_2 (revealing her secret only > AFTER Bob can no longer claim the BTC). In other words: yes, the > protocol can fail if Alice and Bob together work towards that goal. A > feature, not a bug. This won't happen if either of them doesn't want > it to. I imagine this is difficult to model. Right. But it should be noted that it is not enough that Bob publishes success_tx before refund_tx_1 became valid. The success_tx needs to be confirmed before refund_tx_1 became valid. Only Bob can spend success_tx so this is unlikely to be the practical problem, unless the original fee of success_tx is too small and Bob epically screws up CPFP-ing it. > >Bob will receive BTC, and the LTC can be locked forever, but Bob > >doesn't > care, he got his BTC. > > No, because diagram step 5 comes before step 6 -- Alice won't give > her key until she learns secretBob. I somehow missed it, and steps 5 and 6 in the diagram was not modelled at all (on the other hand, it made the model simpler and I had something working relatively quick). I now made the `signers_map` into variable that can be changed to give Bob the ability to sign for Alice. With that change, step 6 can be modelled, but this will add a bunch of new txs to the model (each Alice&Bob spend will have 'Bob unilateral override' case) _______________________________________________ bitcoin-dev mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
