title: What way to change Hash back to it string in c#
body: <p>I am writing a part of code to change string into hash</p>
  
  <pre><code>String hash = GetHashString("A"); //return 7FC56270E7A70FA81A5935B72EACBE29
  </code></pre>
  
  <p>My question is how can I get back "A" when I pass in the hash code  ?</p>
  
  <blockquote>
    <p>7FC56270E7A70FA81A5935B72EACBE29</p>
  </blockquote>