Post by LORD GAUDY (GROUP)

Direct Instant Payments vs Traditional Payment Apps

Question: What prevents someone from having a duplicate wallet on two offline devices and sending payments to two different recipients? Double spending was prevented until both recipients tried broadcasting while back online, with the first valid broadcaster.

Answer: Two people who received transactions spending the same UTXO are stopping them. They have evidence of the fraud (the perpetrator’s signature) and identifying information (identity key and face-to-face interaction). This prevents fake cash fraud. You don’t accept cash from unknown individuals or those you can’t contact for complaints. If caught, you make a criminal complaint. You don’t make high-value transactions offline. This is a convenience that requires trust between counterparties, but no third-party trust.