If you aren't using atomic trading how can you possibly claim decentralized exchange? Otherwise parties can just double spend. There was no mention of double spend or atomic trade in the whitepaper please explain. Users can double spend by simply mining their own transactions. If you use an escrow account then it is not decentralized either because that allows a 2 of 3 collusion attack. And 2 of 2 accounts require microtrading. What protocol is being proposed here?