One of the key components of an e-commerce web site is credit card processing capabilities. One such credit card processing service, that is supported by PHP, is CashRegister, from CyberCash. The CashRegister service enables merchants to make financial transactions over the Internet in real-time. CashRegister works by first you (the merchant) receiving an order request from a customer and sending an authorization request to the CashRegister server. Next the CashRegister server returns either an approved or declined message back to you. If the authorization is approved the order request is completed and the customer receives their goods or services. Communications are encrypted using SSL and Triple DES at the various stages in the process. For a more detailed overview check out the CyberCash web site.

The interface to CyberCash that we will be using is in this article is CyberClass. CyberClass was developed by myself and is an adaptation and enhancement to the original CyberLib written by Timothy Whitfield. CyberClass is a duplication of CyberCash's standard API, is object-oriented and includes automatic configuration.

If you decide that you want to use the CashRegister as a credit card payment solution, the first step is to register at the New Merchant CashRegister Registration. Once you have successfully registered you will have received a user name, password and Merchant ID. Next you will need to get your private encryption key, which are used to encrypt your communications. To do so, go to the Merchant Control Panel, then the Merchant Key Exchange and get your encryption keys.