title: How does one go about reverse engineering an algorithm?
body: <p>I'm wondering how does one go about reversing an algorithm such as one for storing logins or pin codes.</p>
  
  <p>Lets say I have an amount of data where:</p>
  
  <pre><code>7262627 -&gt; ? -&gt; 8172
  
  5353773 -&gt; ? -&gt; 1132
  </code></pre>
  
  <p>etc. This is just an example. Or say a hex string that is tansformed into another.</p>
  
  <p><code>&amp;h8712 -&gt; &amp;h1283</code> or something like that.</p>
  
  <p>How do I go about starting to figure out what that algorithm is? Where does one start?</p>
  
  <p>Would you start trying different shifts, xors and hope something stands out? I'm sure there's a better way as this seems like stabbing in the dark.</p>
  
  <p>Is it even practically possible to reverse engineer this kind of algorithm?</p>
  
  <p>Sorry if this is a stupid question. Thanks for your help / pointers.</p>