Those card readers also typically have photodiodes in them and numerous tamper switches pressed to the case to wipe their internal memory if tampered. Just to be clear I'm not talking about EPROM - they have actual photodiodes inside along with physical switches and a coin battery that will wipe the ROM if tampered.
Fascinating! Is there more detail somewhere on this stuff? Its like a bomb squad drama, making a dam for liquid nitrogen to cool the coin cell below the voltage it can detonate the.. I mean clear the rom, opening the case in a dark tent around the device etc.
Those card readers also typically have photodiodes in them and numerous tamper switches pressed to the case to wipe their internal memory if tampered. Just to be clear I'm not talking about EPROM - they have actual photodiodes inside along with physical switches and a coin battery that will wipe the ROM if tampered.
It's common to have the tamper switches trigger if you drop the terminal. They'll need to be re-flashed from scratch when that happens. eg. https://stackoverflow.com/questions/33872627/how-to-fix-tamp...
Anyway the TLDR is that the Card Reader part of any POS system is reasonably secure.