– How could an ID card be read through RFID protection?

Question

My wallet has RFID protection, and I tested that my debit and credit cards cannot be read by the readers (vending machine, supermarket, vendors etc.).

However, my student ID can be scanned and read through the wallet. (It sits behind a credit card, so it’s not in a section without RFID protection.) How is this possible?

In: 0

Answer 1

Many proximity cards (especially HID branded ones in my experience) use a different frequency than the 13.56 MHz used for NFC and contactless credit cards.

For example, some HID branded prox cards use a 125khz band, US passport cards use 900mhz band

It could be possible that a sleeve was only designed to mitigate only certain frequencies.