I just created this "form key" library, need suggestions

Code:

&lt;?php



#doc

#    classname:    Form_Key

#    note:        Prevents other sites from sending post data to forms on your site

#/doc



class Form_Key 

{

    #    internal variables

    private $form_key;

    private $old_form_key;

    private $ci;

    

    #    __construct

    function __construct()

    {

        // Load additional libraries

        $this->load->library('session');

        // Get instance

        $this->ci =& get_instance();

        

        // Checks if the session form_key is set, if true, assign the session's value to our old_form_key variable

        if (isset($this->ci->session->userdata('form_key'))

        {

            $this->old_form_key = $this->ci->session->userdata('form_key');

        }

    }

    ###

    

    #    generate_key

    function _generate_key()

    {

        $ip = $_SERVER['REMOTE_ADDR']; // User's IP address

        $uniqid = uniqid(mt_rand(), TRUE); // Generates a random key

        return sha1($ip.uniqid); // Return the newly generated key

    }

    ###    

    

    #    output_key

    function output_key()

    {

        $this->form_key = $this->generate_key(); // Generates a unqiue key using our _generate_key method

        $this->ci->session->set_userdata('form_key', $this->form_key); // Sets a new session called form_key with our new unique key

        echo '&lt;input type="hidden" name="form_key" id="form_key" value="'.$this-&gt;form_key.'" />'; // Simple input with our key as the value (hidden)

    }

    ###

    

    #    validate

    function validate()

    {

        return $this->input->post('form_key') == $this->old_form_key;

    }

    ###



}

###



### end of library

Code:

&lt;?php



#doc

#    classname:    Formkey

#    scope:        Public

#

#/doc



class Formkey extends Controller

{

    #    __construct

    function __construct()

    {

        parent::Controller();

        

        // Load additional libraries

        $this->load->library('formkey');

    }

    ###    

    

    #    index

    function index()

    {

        $this->form();

    }

    ###

    

    #    form

    function form()

    {

        $data['form_key'] $this->formkey->output_key();

        $this->load->view('test_view', $data);

    }

    ###

    

    #    validateform

    function validateform()

    {

        if ($this->formkey->validate())

        {

            // Success! Go on with validation (e.g. form_validation)

            

            // If this method of doing it is bad practice, would it be any better

            // to make the variable old_form_key public in the library

            // and apply the session's value to a var in this validateform method

            // and then use the form_validation class for the final validate?

            // Please, any suggestions!

        }

        else

        {

            $data['err_msg'] = "Key is invalid!"; // Redirect user back to the form view and display error message

            $this->load->view('test_fail_view', $data);

        }

    }

    ###



}

###



### end of controller

Code:

&lt;html &gt;

&lt;head&gt;

    &lt;title&gt;Making our forms secure using form keys!&lt;/title&gt;

    &lt;meta http-equiv="Content-type" content="text/html; charset=UTF-8" /&gt;

    &lt;meta name="description" content="apple juice addict" /&gt;

&lt;/head&gt;

&lt;body&gt;

    &lt;form method="post" action="formkey/validate" id="test_form" name="test_form"&gt;

        &lt;?=$form_key?&gt;

        <label for="email">Email</label> &lt;input type="text" name="email" id="email" /&gt;&lt;br />

        <label for="website">Website</label> &lt;input type="text" name="website" id="website" /&gt;&lt;br />

        &lt;input type="submit" name="submit" id="submit" value="Submit!" /&gt;

    &lt;/form&gt;

&lt;/body&gt;

&lt;/html&gt;

Code:

&lt;html &gt;

&lt;head&gt;

    &lt;title&gt;Making our forms secure using form keys!&lt;/title&gt;

    &lt;meta http-equiv="Content-type" content="text/html; charset=UTF-8" /&gt;

    &lt;meta name="description" content="apple juice addict" /&gt;

&lt;/head&gt;

&lt;body&gt;

    <p>&lt;?=$err_msg?&gt;</p>

&lt;/body&gt;

&lt;/html&gt;

Code:

// From this

if ($this->input->post('form_key') == $this->old_form_key)

{

    return TRUE; //  The key is valid, return true

}

else

{

    return FALSE; // The key is invalid, return false

}



// To this

return $this->input->post('form_key') == $this->old_form_key;