title: How ciphertext was generated in card reader using DUKPT encryption?
body: <p>For </p>
  
  <pre><code>`BDK = "0123456789ABCDEFFEDCBA9876543210"` `KSN = "FFFF9876543210E00008"` 
  </code></pre>
  
  <p>The ciphertext generated was below</p>
  
  <pre><code>"C25C1D1197D31CAA87285D59A892047426D9182EC11353C051ADD6D0F072A6CB3436560B3071FC1FD11D9F7E74886742D9BEE0CFD1EA1064C213BB55278B2F12"`
  </code></pre>
  
  <p>which I found <a href="https://github.com/Shopify/dukpt/blob/master/test/decrypter_test.rb" rel="noreferrer">here</a>. I know this cipher-text is based on BDK and KSN but how this 128 length cipher text was generated? What are steps involved in it or algorithm used for this? Could someone explain in simple steps. I found it hard to understand the documents I got while googled.</p>