I'm a newbie here, and I don't have a lot of experience with reverse engineering, so I'm asking for your help.
I have dumped a Mifare Classic card several times, because I wanted to try understand the data that was written on it. I compared the dumps and succeeded in understanding where the data was and in which format.
The data is stored in 8 bytes split into two groups. At the end of each group there is another byte which I suspect is some sort of checksum. Here is the data I got until now:
00 BB and 01 0B have a checksum byte of 45 01 6F and 01 0B have a checksum byte of B5 01 90 and 02 58 have a checksum byte of BC 01 90 and 00 C8 have a checksum byte of 56 00 00 and 00 00 have a checksum byte of 64
Can you help me find out how the checksum byte is calculated? Thanks.