//sha1()函數， "安全散列算法（SHA1）"
function create_unique() {
    //客戶端+IP+時間戳+隨機數組成的字符串
    $data = $_SERVER['HTTP_USER_AGENT'] . $_SERVER['REMOTE_ADDR'] .time() . rand();
    //使用sha1加密
    return sha1($data);
}

$newhash = create_unique();
echo "token方法1: ".$newhash."<br>";

$token = md5(uniqid(rand()));
echo "token方法2: ".$token;