| submitted by /u/undertheradar48
Consider there are $ n$ parties $ P_1,\cdots,P_n$ having their identities as $ id=1,\cdots,n$ . They wish to calculate $ f(s_1,\cdots,s_n)=(s_1+\cdots+s_n) \bmod n$ , where $ s_i$ are individual parties secret. Parties are using Bitcoin to execute the protocol.
Now, I want to handle the function $ f$ if some of them leave the protocol. Suppose $ P_3$ and $ P_4$ said in the beginning that they might exit the lottery in mid-way. Their final decision of leaving/continuing will be known in the real-time in mid of execution of the protocol. If both of them leaves the protocol then $ s_3$ and $ s_4$ should not be included in computing $ f$ , and the winner should not be among $ P_3$ and $ P_4$ . But if either of them continues the protocol then their input should be included in computing $ f$ .
I somewhat understand the two way channels used in lightning. But I fail to see how trust is avoided.
If I’m the middle node I’m perfectly fine with forwarding a payment, if I received the payment first. The initial payer can reason that he will only make the payment if all intermediate nodes have shifted the payment to the receiver. It seems like until at least one party takes the risk the payment is in some kind of Mexican standoff.
How is this avoided / cryptograpically enforced?
The present invention relates to a system and method for trading digital virtual money having a blockchain between parties, which guides to facilitate a URL-based simple trade without recognising a public address formed with 32 bytes or more whenever trading digital virtual money having a blockchain between parties, thereby facilitating trade without a QR code for separate bitcoin payments, and preventing a number of disadvantageous effects of the QR code for bitcoin payments involving trade…