Efficient algorithm/technique to encrypt and decrypt sensitive data in PHP/MySQL and CI context.

[eluser]mr_prasanna[/eluser]
That's right. But with some gateways there is no easy method to create billing agreements and bill for a variety of amounts (within a limit though) whenever you want. Like in case of a telephony services portal, customer might want to upgrade/degrade to a plan apart from periodic billing we will have to bill them for few extra bucks. With PayPal there is something called reference transactions but it has it's own limit. Also, if you want to offer trial services, where you charge 0 for few weeks and then bill some $x all this is a slight complex thing. Above all, in case of trial services to avoid fraud we need to verify credit card numbers...
Anyways...it's worth checking with Auth.net or FirstData type of processors than with WorldPay or Paypal. Thanks for all the help.