How do electromagnetic chips like those on cards exactly work and direct EMVs coming from the reader?

Question

I know they communicate and am not exactly interested in the description of the transaction itself – rather, the enguneering and physica behind it.

In: 2

Answer 1

Do you know how if you sing to a tuning fork at just the right frequency, it will sing back? Now attach a tiny computer to the tuning fork that can put the fork into and out of tune. The computer can also listen to the tuning fork and detect subtle changes in your singing of it’s note. You can communicate to the computer by modulating the note you are singing in a sort of Morse code. The computer can communicate with you by modulating the tuning of the fork so you can hear it going into and out of tune with a Morse code pattern.

This is how nfc/RFID/tap payment systems work (sort of, but more complicated) except with electromagnetic waves instead of sound waves.