How to develop a basic user-authentication system with PHP

By Ben on April 9th, 2008

Let’s start with some background information.

User authentication systems have been used since the dawn of the Internet, and even before then. From MySpace, Yahoo! Mail, GMail, to logging in to your Windows (or other) desktop; user authentication systems serve several purposes, with the main being to protect or limit access to certain information and/or data.

When developing dynamic web systems you will always need some form of user authentication system to control access to certain features within the system. It is always a good idea to limit access to certain features of your system to specified people/things, so this tutorial will definitely be put to good use if you need it.

What You Need Before We Begin:

Your own domain and webhost account. - While you can possibly get a free host somewhere to host your website, you will always be looked at as an amateur if you do not own your own domain. You can still utilize and follow this tutorial without your own domain but we do not recommend it. Also, you can still follow this tutorial without a webhost account but you will not be able to utilize and/or setup the user system without one.
We recommend GoDaddy for your domain registrar and LunarPages for your webhost, as both are cheap and very reliable.
PHP 5+ installed on your webhost. - The PHP code used in this tutorial was coded to work with PHP version 5 but is completely compatible with newer versions of PHP (6).
MySQL 4+ installed on your webhost. - The MySQL queries used in this tutorial were coded to work with MySQL version 4.0 but is completely compatible with newer versions of MySQL.
Plain Text Editor. - You will undoubtedly need a text editor to write, edit and save your code (files). We recommend WeBuilder.
FTP Client. - You will undoubtedly need an FTP client to transfer your files from your computer to your webhosts server. We recommend CuteFTP.
Beginner PHP knowledge. You will need to know at least how to print text/code blocks to the browser window, basic string manipulation techniques, and how to properly manipulate and modify cookies with PHP to follow this tutorial. We recommend going over our introductory PHP articles, starting with Introduction To PHP5: Part #1: What Is PHP?.
Excelled (X)HTML knowledge. You will need to know the HTML markup language through and through. You may still be able to follow through the tutorial though. We recommend going over our introductory HTML articles, starting with Introduction To HTML: Part #1: What Is and What You Need.
Beginner MySQL knowledge. - You will need to know how to code basic MySQL queries. We haven’t produced any SQL-related tutorials as of yet so sorry about that.