Ion Auth - Lightweight Auth System based on Redux Auth 2

[eluser]Sinclair[/eluser]
Another question about the Ion Auth...

I need to create users in a Database Procedure, using PlpgSQL language... so I need to understand a litle bit better the table "USERS" and the account creation process.

My firts question, what is the "salt"?

My second question goes to the password storage. I need to generate the password encryption in the Database procedure. What kind of encryption is the Ion Auth using?

I have read some code:

Code:

// IP Address
        $ip_address = $this->input->ip_address();
        $salt = $this->store_salt ? $this->salt() : FALSE;
        $password = $this->hash_password($password, $salt);

Best Regards,

Sorry my poor english.