form/credentials validation

[eluser]yacman[/eluser]
Security is a broad subject which should be researched and understood by any systems designer. Research patterns to protect your information and systems, this goes beyond what you write in PHP to your server configurations, database configurations and most importantly the network you are hosted on.

With that in mind, I would suggest instead of rolling your own authentication security, utilize an off the shelf CI Library or Spark. These off the shelf libraries like Tank Auth use security patterns to salt and crypt passwords, and have security patterns for registration like only allowing a user to log in after they have validated their email address via a unique link.

You can use these libraries and class methods in your code,

In the end, Google for different authentication libraries CI has and see what meets your needs the best. If it's open source, you can just rip it apart and use what you want.