Authentication failure for Mifare 1K NFC tag using ACR122U NFC reader

Question

I always get the failure result when using ACR122U tool to authenticate Mifare 1K NFC tag, but I can use Android phone to read/write this tag.

ACR122U Load Authentication Keys
< FF 82 00 00 06 FF FF FF FF FF FF 
> 90 00 
< Key Structure: 00    < Key Number: 00
< Key: FF FF FF FF FF FF
Load Authentication Keys Success

ACR122U Authentication
< FF 86 00 00 05 01 00 00 60 00 
> 63 00 
Operation failed

Answer 1

Your remark about an Android phone being able to read and write this tag suggests it is formatted to contain NDEF data. Instead of the factory default key 0xFFFFFFFFFFFF, you could try to use the MIFARE Application Directory key 0xA0A1A2A3A4A5 for the first sector (blocks 0-3) and the NFC Forum key 0xD3F7D3F7D3F7 for the following sectors. See NFC Type MIFARE Classic Tag Operation for more details.