Sending encrypted credit card data

I am sending data to a Credit Card processing firm via POST. The data is being received properly, however, I am getting a message informing me that the data was not encrypted. The Perl example the firm provides uses SSLeay.PM. This is my first encounter with sending "encrypted" data. Can someone tell me how I can do this with PHP? Many thanks.......... Todd -- Todd Cary Ariste Software todd@aristesoftware.com