title: Best algorithm for hashing number values?
body: <p>When dealing with a series of numbers, and wanting to use hash results for security reasons, what would be the best way to generate a hash value from a given series of digits?  Examples of input would be credit card numbers, or bank account numbers.  Preferred output would be a single unsigned integer to assist in matching purposes.</p>
  
  <p>My feeling is that most of the string implementations appear to have low entropy when run against such a short range of characters and because of that, the collision rate might be higher than when run against a larger sample.</p>
  
  <p>The target language is Delphi, however answers from other languages are welcome if they can provide a mathmatical basis which can lead to an optimal solution.</p>
  
  <p>The purpose of this routine will be to determine if a previously received card/account was previously processed or not.  The input file could have multiple records against a database of  multiple records so performance is a factor.</p>