Originally Posted by caspritz78

The frequency to read the RFID chip in a passport is 13.56 MHz. As higher a frequency gets as harder it is for it to penetrate objects. 13.56MHz are considered to be High. So there is a chance that thick aluminum foil might do the trick. I would say it will definitely make it impossible to read the chip from a larger distances but in very close proximity like a few inches I'm not so sure.