title: Storing encrypted credit card numbers in a SQL database
body: <p>I was wondering what the best approach is to store <strong>encrypted credit card numbers</strong> in a SQL database for <strong>C#</strong> (.net framework).  Should I do it manually by using <code>String/SecureString/Byte Array</code> with some sort of <code>symmetric encryption</code>? </p>
  
  <p>I heard that for an alternative (and probably the easier option), a <strong>service provider</strong> (which you place the transaction with) will give you a <code>key</code> that can be used to retrieve transaction information.  I don't know how to go about this approach, but is this the better option?  I want the most safest and most secure option.  I want to be <strong>PCI compliant</strong> as well.</p>