title: SmartCard MUTUAL AUTHENTICATION
body: <p>Hi I'm looking for information about working MUTUAL AUTHENTICATION with SmartCards, I wonder if you can help me.
  I'm working on reverse engineering apdu commands and would like to know how to calculate MAC.
  For example I have the following:</p>
  
  <pre><code>APPLET: A4 00 04 0C XX XX XX
  APDU: 00 84 00 00 08 C9
  TRX: 00 82 00 00 28 [seed bytes Transformed enc mac ...] 00
  TRX: B0 0C 0D 81 00 97 01 5D 8E 08 [MAC] 00
  </code></pre>
  
  <p>The first two commands I understand them perfectly, but starting in the third one 00 82 is where I would like to know how to calculate the MAC and what follows, to make the readings
  I would like to know information and documents to read and learn more about MUTUAL AUTHENTICATION</p>