I'm using ACR1222L NFC smartcard reader with Mifare Plus cards (Security Level 0 as of now; manufacturer default keys A and B). I tried a variety of commands to load authentication key into the reader:
FF 82 00 00 06 FF FF FF FF FF FF
FF 82 00 01 06 FF FF FF FF FF FF
FF 82 20 00 06 FF FF FF FF FF FF
FF 82 00 00 06 A0 A1 A2 A3 A4 A5
FF 82 00 00 06 D3 F7 D3 F7 D3 F7
... and others ...
All of them are returning the error status:
63 00 (Operation Failed)
What could be wrong? I have searched long and wide for a hint, but many other questions are about failed authentication or failed read after successfully loading authentication key with one of the above commands, and they are often based on a different device (ACR122U).
I noticed that the reader does not even respond to the command when a card is not present. Should a card be present on the reader for it to load authentication key?
To be able to use the commands such as "Load Authentication Key", "Authentication (of a block)", Read, Write, Update, etc, the card has to be in Security Level 1 or higher.
There are certain commands to move the card from Security Level 0 to Security Level 1 by loading several relevant keys into the card. Please contact ACS to obtain these commands as they are not publicly documented.