This method has the advantage that it can be used to create a decentralized off chain minimal trust derivatives exchange as well. I'll have time to write up the technique next week, hopefully.
I don't fully understand your comment and guess it's because this is a complex detail of your implementation. I guess these off-chain-transactions are by far no common knowledge within the bitcoin community precisely because of their complexity. Not Zero-Coin-complexity but still an order of magnitude more complex than the Satoshi whitepaper.
Edit: @blueadept would you share my opinion on the potential of off-chain-transactions if implemented your way? I mean this list:
- instant (as in milliseconds)
- free-ish (as in "as much as 0.01CPU-second and a 1kB package over the network costs")
- arbitrarily small (as in "1 Satoshi minimum")
- more private (in a sense, maybe)
- without third party risk (and minimal third party risk for a full peer to peer version)