Storing Credit Card Numbers, etc.

PHP Fellows: Thanks for taking the time to look at this. I'm new to PHP and to e-commerce. Needless to say, I've done a lot of studying over the last few weeks and I'm ready to dive in head first! I'll be building an e-commerce site and I'll be using PHP. I'd like customers to have the option of saving their information so that they don't have to enter it each time they purchase -- much like Buy.com does or like Amazon.com's One-Click feature. This means that the customer will be storing information like one or more credit cards, shipping addresses, billing addresses, etc. I'm planing on storing all information in flat files so that I don't have the additional expense of using MySQL (My ISP is charging 24.95/month extra for MySQL service). So the question is: How can I store each customer's information safely? Can I use .htaccess and .htpasswd to help me out? Or don't they even apply? My intention is to store the user's password encoded with md5 or something and also to develop my own cipher for disguising the credit card numbers as well. Any suggestions? Thanks, Christopher Raymond ------------------------------------------------------ O A S I S N E T W O R K S ------------------------------------------------------ INTERACTIVE FLASH MEDIA PRODUCTION HTML & JAVASCRIPT WEB SITE DEVELOPMENT MACINTOSH TROUBLESHOOTING, REPAIR & NETWORKING ------------------------------------------------------ WEB: http://www.oasisnetworks.com PHONE: 612.706.0767