Quote from: SebastianJu on March 11, 2016, 04:06:41 PM

Additionally, who has to send first to the escrow address?

When the buyer has to send first 2x then the seller is in favor risking nothing. If the seller sends 1x first then he would be in risk of losing 1x.

If you read the thread where Serge V. described the concept, you'd have seen that neither sends first:

Quote from: Serge V. on March 09, 2016, 03:38:44 PM

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Here is an example of the escrow scheme that motivates scammer to be honest to his trading partner:
1. The agent creates a transaction, according to which the buyer collateral & the buyer payment for goods (2x) + the seller collateral (1x) will be sent to the created from their public keys MultiSig address.
2. The buyer and the seller checks and sign the transaction, the transaction is broadcasted to the network.
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So, the idea here is that a facilitator (they can be the buyer, seller, an escrow or agent, or whatever you like), is given a list of inputs that each party is planning on using to fund the transaction. The facilitator then crafts a single unsigned transaction that uses the necessary inputs from BOTH parties and funds the 2-of-2 address with a single output (and adding additional outputs to send any required change back to the parties). This transaction is unsigned and therefore not useful to the facilitator to steal anything from anyone. The facilitator then provides the unsigned transaction to each of the parties so they can review it to make sure it does what it is supposed to do. Once the two parties are happy with the transaction, they can both sign it. Since the transaction simultaneously uses inputs from BOTH parties, it isn't useful when only one party has signed it. Therefore, it doesn't matter which of the two parties signs first. After BOTH parties have signed the transaction, any of the three parties (buyer, seller, facilitator) can broadcast the transaction. When the transaction has confirmed, the funds of BOTH parties will simultaneously be trapped in the 2-of-2 transaction until BOTH parties agree to release it.

Quote from: SebastianJu on March 11, 2016, 04:06:41 PM

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Even when both sent. Then the seller risked only 1x and the buyer 2x. At this point the buyer is more at risk. The seller can extort for more than his 1x.
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He can, or the buyer can extort from the seller. It's a bit like the "mutually assured destruction" that was supposed to prevent nuclear war. As long as the "collateral" is large enough that neither party is willing to lose the money, and both parties are willing to walk away and lose their money in order to prevent the other party from gaining anything inappropriately, the scammer can't extort anything. The scammer can force the victim to lose money, but they can't gain anything for themselves without the victims cooperation.

If the victim is more desperate than the scammer to at least get some potion of their money back, then the scammer can convince the victim to give up a portion of their money in order to get a little bit of it back.

If the scammer is more desperate than the victim to at least get some potion of their money back, then the victim can convince the scammer to give up a portion of their money in order to get a little bit of it back.

So, if the seller risks 1 BTC, and the buyer risks 2 BTC.

The buyer can extort the seller, by demanding that the seller sign a transaction to release 2.1 BTC from the 2-of-2 so that the Seller only gets 0.9 BTC back. The buyer will win this extortion if the seller is desperate enough.
The seller can extort the buyer, by demanding that the buyer sign a transaction to release 1.1 BTC from the 2-of-2 so that the Buyer only gets 1.9 BTC back. The seller will win this extortion if the buyer is desperate enough.

As Serge V. pointed out, if the victim is always willing to walk away with a complete loss of everything that they put into the transaction, then the scammer can't gain anything, all the scammer can do in that situation is lose their own money and force the victim to lose money at the same time. Once the transaction is funded and confirmed, the entire thing turns into a negotiating contest where each party has the opportunity to try to negotiate the best possible result for themselves while trying to find a result that the counter-party will be willing to accept.