i've been in many discussions on this exact topic and have yet to here a good response. Even peter todd's double spending could be prevented with a simple smart wallet that checks for and flags any transactions that don't come from "vanilla" sources. If there is anything even remotely suspicious, then the transaction is flagged, and the customer is not allowed to leave the store with the product.
Anyone with more technical knowledge care to refute satoshi here?
So what happened to Satoshis theory As this person stated?
Satoshi's comment PASTED IN HERE VV
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I believe it'll be possible for a payment processing company to provide as a service the rapid distribution of transactions with good-enough checking in something like 10 seconds or less.
The network nodes only accept the first version of a transaction they receive to incorporate into the block they're trying to generate. When you broadcast a transaction, if someone else broadcasts a double-spend at the same time, it's a race to propagate to the most nodes first. If one has a slight head start, it'll geometrically spread through the network faster and get most of the nodes.
A rough back-of-the-envelope example:
1 0
4 1
16 4
64 16
80% 20%
So if a double-spend has to wait even a second, it has a huge disadvantage.
The payment processor has connections with many nodes. When it gets a transaction, it blasts it out, and at the same time monitors the network for double-spends. If it receives a double-spend on any of its many listening nodes, then it alerts that the transaction is bad. A double-spent transaction wouldn't get very far without one of the listeners hearing it. The double-spender would have to wait until the listening phase is over, but by then, the payment processor's broadcast has reached most nodes, or is so far ahead in propagating that the double-spender has no hope of grabbing a significant percentage of the remaining nodes.
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Or is this what payment processors do already and we are talking about something quicker here?
Just curious has anyone looked at the other coins, and why are some stating HIGH security even more than BTC or same + MUCH faster transaction times... I just don't get it, cant we just implement the same thing? Many test coins around.