title: query string parameter obfuscation
body: <p>I want to obfuscate one query string parameter in ASP.NET. The site will have a high volume of request, so the algorithm shouldn't be too slow.</p>
  
  <p>My problem is that all the algorithms I found result in unwanted characters (like +/=) </p>
  
  <p>Here is an example of what i want to achieve:</p>
  
  <pre><code>www.domain.com/?id=1844
  </code></pre>
  
  <p>to </p>
  
  <pre><code>www.domain.com/?id=3GQ5DTL3oVd91WsGj74gcQ
  </code></pre>
  
  <p>The obfuscated param should only include <strong>a-z and A-Z and 0-9</strong> characters.</p>
  
  <p>I know I can encrypt using base64, but this will generate unwanted characters such as <code>/</code> or <code>=</code> or <code>+</code>.</p>
  
  <p>Any idea what algorithm can be used?</p>
  
  <p><strong>Update:</strong>
  I'm aware of UrlEncoding , i want to avoid encoding the string.
  because that will generate charaters like %F2 or %B2 in the url.</p>