title: What is the equivalent of the Java method 'MessageDigest.getInstance()' in c# ?
body: <p>What is the equivalent of this in C#?</p>
  
  <pre><code>MessageDigest md = MessageDigest.getInstance("SHA");    
  byte[] after = md.digest(before);    
  String securityHash =new sun.misc.BASE64Encoder().encode(after);    
  </code></pre>
  
  <p>The source is in Java</p>