Hashing is the generation of random numbers from certain data. The feature of this function is to output the same hashed value from any value, and it is impossible to derive the original data from the hashed value. The hash function is used for user authentication etc.
Know as a hash function, hash algorithms such as MD5 and SHA1 can now examine the output with brute force to get the original input.
$password = "password";
echo sha1($password) . "<br>";
echo md5($password) . "<br>";
echo hash('sha256', $password) . "<br>";
