So the other party can pull out before the trade is done should the market move against them ~30 minutes later (when they actually have to complete)
Until this TECHNICAL issue is resolved, I don't think any DLEX can really work..
The 'hack' is easy.
There's an order book, with 3 SELL orders below(at a lower price then) yours.
You initiate a trade with those three, to get them out of the way, never intending to complete.
New user turns up and sees your SELL order is the first available. Boom.
The ONLY 'hack-fix' at the moment is not decentralised, but centralised. Which kind of defeats the whole point.
..
It'll be some clever trick, like Tier Nolan's original and brilliant Atomic Cross Chain Transfer. No one's come up with it yet though..
Can you explain how this issue can work against the BitShares dex?
Actually BitShares is an 'onchain' exchange. What I mean is that the assets you trade are on the Bitshares Chain itself. This means the 'hack' does not work. But.. you have not really traded BTC for ETH.. You have traded a 'market pegged asset'.
When you want to trade BTC for ETH on BitShares, you actually trade a BTC 'token' against an ETH 'token' that both live on the BitShares Chain, and THEN have to convert those tokens, into either actual BTC or ETH.
So although the Chain itself is decentralised, and so is the trading, you still have to cash out, and this requires finding someone to exchange your BitShares tokens with.. hmm..
This is not the same as actually trading BTC you own, for real ETH. It's close-ish, but you are not sure you can even convert your 'tokens' into the real thing.
I think this is what prevents many of us from using onchain asset exchanges.. after all NXT has had one for-ever..