In this new post to his site Kevin Schroeder has a new post with his take on generating more secure CSRF tokens for use in your site.
In researching the second edition for the IBM i Programmer’s Guide to PHP Jeff and I decided to include a chapter on security since we really didn’t talk much about it in the first edition. I’m talking about cross site request forgeries right now and I wanted to make sure that what I was going to suggest would not break the internet in some way. I did some Google searching to see what other people were recommending.
Most of the examples he saw used md5, uniqid and rand to create a randomized hash. He suggests an alternative - a method using the hash_hmac and openssl_random_pseudo_bytes methods to generate a sha256 hash for use in your page's submissions.