4 ms·

Surely that’ll get you a one use token but not data good for repeat use? In addition you would have to send that to the network as a retailer yourself. So it wo

• MBCook 4y ago
  It’s completely useless. Because the terminal you’re using is involved in what gets signed, even if you replayed the data to a different but identical contactless terminal (say the next gas pump over) the signatures would fall apart and it wouldn’t work. The serial numbers and such are different. Also there are transaction counters involved. So even if you could overcome that the processor would see that your card had two transactions with counter 268753 and reject the second. The terminal also has its own transactions counter mixed in too. And even if you could overcome those I’m almost positive that timestamps are involved too. So even if you could replay the transaction to the same exact terminal and get around the transaction counter issue the time would be different and I think that would cause it to fail. It really is a well designed system. It follows that software law that people can know absolutely everything about the process and it’s still secure as long as the private keys aren’t given away.