Generating confirmation code for an email confirmation

1) Create an Activated Field in Database

2) After registration the Email is sent

3) Create a Link to include in Email,Use a Unique identifier It would look something like this

Welcome Username Thanks for registering.

Please Click on the Link below to activate your account

domain.com/register.php?uid=100&activate=1

4) Update the Activated Field to true

_{(source: jackborn.com)}

$email_encrypt = urlencode($email);
$special_string = 'maybeyourcompanynamereversed?';
$hash = md5($email_encrypt.$special_string);

Here is the link that is sent to the email that was provided:

http://yourdoman.com/confirm.php?hash='.$hash.'

The actual link will look something like this:

http://yourdomain.com/confirm.php?hash=00413297cc003c03d0f1ffe1cc8445f8

$random_hash = md5(uniqid(rand(), true));

That will be 32 alphanumeric characters long and unique. If you want it to be shorter just use substr():

$random_hash = substr(md5(uniqid(rand(), true)), 16, 16); // 16 characters long

Alternative methods to generate random data include:

$random_hash = md5(openssl_random_pseudo_bytes(32));
$random_hash = md5(mcrypt_create_iv(32, MCRYPT_DEV_URANDOM));

// New in PHP7
$random_hash = bin2hex(random_bytes(32));