title: What determines the SAK of a Mifare device?
body: <p>I have a Mifare fob and a magic Mifare Classic card. When I fully clone the fob onto the card, the SAK found from the card is <code>0x88</code>, despite a SAK of <code>0x08</code> on the fob.</p>
  
  <p>If I change the sixth byte of block 0 on the card from <code>0x88</code> to <code>0x08</code>, the SAK changes accordingly. However, the fob holds a value of <code>0x88</code> at that position whilst reporting a SAK of <code>0x08</code>. So, what determines the SAK such that two cards with supposedly identical data can report different values for it?</p>