I'm trying to execute an unusual 3-way transaction, where in one of the parties is not known at the start.
PartyA would initiate the transaction, and provide funding. My thought was that he would transfer 1BTC to a dedicated wallet.
He'd then also start the transaction, and name Party B as one required signature.
For the third signature, he'd approach 5 random strangers. He'd give them any and all information necessary to complete the transaction (including the private key of the wallet he just made if nec).
The first one who could propose a deal, and convince PartyB to accept it, would receive their share of the money.
For instance, c1 might offer B to split 80/20, where-as c2 offers to split 50/50. PartyB signs the proposed offer from c2, and it can then execute.
It looks like there might be a way to do this with multiple signatures and p2sh, but I'm not quite sure how to make it work yet. Any thoughts or comments welcomed.