php - 我需要帮助在我的网站联系表中添加一个简单的数学验证码

Question

我想在我的 php 表单中添加一个简单的数学验证码，，，

这是完整的表单代码，但它不起作用。

这是代码的链接：http: //thefairygodsister.com/testtest/index%20-%20Copy.txt

Answer 1

You can also make a "faux" maths captcha like here that works on the very simple principal that the text needed to be inputted is fixed and indicated in an image - works perfectly at stopping bots sending you random emails without over complicating it.

Answer 2

采取的基本步骤是：假设这是一个加 2 个数字的数学

$num1 = rand(15,50);
$num2 = rand(2,9);
$salted_answer = $num1+num2 + 187; //thats some salt

将 salted_answer 放入表单上的隐藏输入中。

检查时：

if ($_POST['salted_answer'] - 187 == $_POST['answer']) { 
  echo "all is good";
  // do your processing 
}

而已。