title: encryption and decryption algorithm in Rails
body: <p>I would like to <strong>encrypt</strong> and <strong>decrypt</strong> one attribute string value of a <strong>model</strong> by using <a href="http://en.wikipedia.org/wiki/Advanced_Encryption_Standard">AES</a> algorithm.</p>
  
  <p>I am wondering in <strong>Rails</strong>, what is the easiest way to have it? Is there any <strong>AES</strong> <code>gem</code> library which can be used directly? And how to use it?</p>
  
  <p>Basically I need some guideline on how to apply <strong><a href="http://en.wikipedia.org/wiki/Advanced_Encryption_Standard">AES</a></strong> encryption/decryption in Rails app.</p>
  
  <p><strong>------- update -------</strong></p>
  
  <p>I just notice that there is <a href="http://rubygems.org/gems/aes">AES gem</a>. If I add this gem into my GemFile, how can I use it in my application for encryption &amp; decryption?</p>