Several php authentication security method

php_auth.php

function md5_auth() {
    $current_time = time();
    $hash_str = join("", array(MD5_SALT_KEY, $current_time));
    return array(
        'current_time' => $current_time,
        'token' => base64_encode(md5($hash_str)),
    );
}

function swt_auth($parameters) {
    // Build an HMAC-SHA1 signature using the multipass string and your API key
    $signature = hash_hmac("sha1", $parameters, HAMC_KEY, true);
    // Base64 encode the signature
    $signature = base64_encode($signature);
    return $signature;
}