32bits simple hash function in PHP

PHP provides a simple function can hash in 32bits - hash( $algorithm, $key) - it will provide 8 bytes string as hash result.

$key = "Chun Kang";
echo hash("crc32b", $key);

If you want more secure method, you can add salt like below:

function customHash($key, $salt="Genius")
{
    $key .= $salt;
    return hash( "crc32b", $key);

}

$key = "Chun Kang";
echo customHash("crc32b", $key);