Many times, when I talk to someone about InstantX, they answer that nobody is gonna do a double spend attempt just for a latte because it would be too expensive. I'm trying to work on a good answer to this. Beside of the risk of the transaction never getting picked by a miner for reasons such as insufficient fee, I want to be able to explain that 0 confirmations acceptance is a bad solution to a structural problem of Bitcoin. The fact that today there is no big risk for most small purchases doesn't mean that there won't be such risk in the future.
So question for those with a deeper knowledge of networks than me:
Would it be possible to develop a mobile Bitcoin wallet that every time it makes a transaction it broadcasts that transaction and a conflicting one (to another address by the same user)? As I understand it, sometimes the legit transaction would be picked by the network and sometimes it would be the other. Obviously the user of this wallet would have some risk of being caught, but as an advantage he would get a 'free purchase' once in a while. Payment processors could try to fight this by monitoring the network and sending an alert to the point of sale, but that is a dirty patch on top of a bad solution.
So question for those with a deeper knowledge of networks than me:
Would it be possible to develop a mobile Bitcoin wallet that every time it makes a transaction it broadcasts that transaction and a conflicting one (to another address by the same user)? As I understand it, sometimes the legit transaction would be picked by the network and sometimes it would be the other. Obviously the user of this wallet would have some risk of being caught, but as an advantage he would get a 'free purchase' once in a while. Payment processors could try to fight this by monitoring the network and sending an alert to the point of sale, but that is a dirty patch on top of a bad solution.