Default key No. of known systems using it List of those systems Approx. no. of cards using it Approx. % of cards from total Mifare Classic cards
ffffffffffff 1 SKGT
 ? ?
a0a1a2a3a4a5 1 SKGT
 ? ?
b0b1b2b3b4b5 ? ? ? ?
000000000000 ? ? ? ?
4d3a99c351dd ? ? ? ?
1a982c7e459a ? ? ? ?
d3f7d3f7d3f7 ? ? ? ?
aabbccddeeff ? ? ? ?