This is a quote from the book "On Zero Confirmation Transactions" by Chris Pacia
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...l double-spend against us is worth the cost for the improved user experience.
It’s a straw man to suggest we think zero confirmation transactions are “100% safe”. They a
ren’t, but they don’t need to be to serve the purpose.
Given double spend detection, it becomes very difficult to successfully defraud a retail
er. Ideally what you would like to do is broadcast the valid payment, leave the store with the merchandise, then broadcast the double spend. The problem you have is every miner (from the very be...