Have you ever been on one of those websites that asks if you are a robot? Yeah, I know you have, they are everywhere.

您是否曾经访问过询问您是否是机器人的网站之一？ 是的，我知道你有，他们无处不在。

What you might be wondering is why a computer is asking you to prove your humanity and why a robot wouldn’t just lie its way in. After all, it’s not like robots are sworn to an oath of candor. Also, there are videos on the internet with robots clicking the “I’m not a robot” checkbox, so what exactly do these seek to accomplish apart from just being annoying.

您可能想知道的是，为什么一台计算机要求您证明自己的人性，以及为什么一个机器人不会只是撒谎而已。毕竟，这并不是说机器人发誓要坦率。 另外，互联网上有一些视频，其中有机器人点击了“ 我不是机器人 ”复选框，因此，除了烦人之外，这些视频还试图实现什么目的。

Since the dawn of the internet, people have always wanted to keep robots out — not the kind of hardware C3PO robots that click the ‘I’m not a robot’ checkbox in funny videos; software robots that are developed to mimic or automate real user activity. For example, Google has bots called Googlebot whose job is to crawl the web and build a searchable index for the Google Search engine. If I had a website, the Googlebot would visit my site, just like a regular human would, it would then index the page and recursively do the same for all pages with links on that page.

自从互联网诞生以来，人们一直希望将机器人拒之门外-而不是那种在有趣的视频中单击“我不是机器人”复选框的C3PO机器人。 开发用于模仿或自动化实际用户活动的软件机器人。 例如，谷歌有一个名为Googlebot的机器人，其任务是抓取网络并为Google搜索引擎建立可搜索的索引。 如果我有一个网站，则Googlebot会像普通人一样访问我的网站，然后它将对该页面编制索引，并对包含该页面上链接的所有页面进行递归操作。

If you don’t want to allow these robots on your site, there is a standard called the Robots Exclusion Standard which allows you to communicate with bots. You create a robots.txt file and set options in there, specifying where bots are not allowed. The problem is robots.txt is more of a suggestion to bots than a blockade, so it is up to the bot whether it wants to listen to that suggestion or not. Whiles Google and a couple of bots may be ethical enough to listen to this suggestion and leave these sites be, there are a lot of bots out there that require a firmer hand to keep them out.

如果您不想在您的站点上允许这些机器人，则有一个称为“机器人排除标准”的标准，该标准可让您与机器人进行通信。 您创建一个robots.txt文件并在其中设置选项，并指定不允许使用bot的位置。 问题是robots.txt更像是对机器人的建议，而不是封锁，因此，机器人是否要听这个建议取决于机器人。 尽管Google和几个机器人可能合乎道德，可以听取此建议并保留这些网站，但仍有许多机器人需要坚定的手才能将其拒之门外。

Whiles the example of Googlebot is relatively innocuous, there are lots of bots out there that range from nuisance to unethical or evil. Some bots steal information, hack passwords and credentials, misrepresent themselves as human, spam users, bully people on the internet, etc. To give a firmer hand and keep these bots out, that’s where our old friend, the CAPTCHA comes in.

尽管Googlebot的例子相对来说是无害的，但仍有许多从讨厌的东西到不道德的或邪恶的机器人。 一些僵尸程序会窃取信息，破解密码和凭据，将自己伪装成人类，垃圾邮件用户，互联网上的欺凌者等。为了更坚定地阻止这些僵尸程序，我们的老朋友CAPTCHA来了。

Completely Automated Public Turing test to tell Computers and Humans Apart(CAPTCHA) is a test that’s used to determine whether or not a user is human. They do this by presenting problems that pose significant challenges for computers to solve.

告诉计算机与人类完全自动化的公共图灵测试(CAPTCHA)是用于确定用户是否为人类的测试。 他们通过提出对计算机解决重大挑战的问题来实现这一目标。

Text-based CAPTCHAs

基于文本的验证码

Text-based CAPTCHAs

基于文本的验证码

Text-based CAPCTHAs are designed to require the simultaneous use of three abilities;

基于文本的CAPCTHA设计为要求同时使用三种功能。

• Invariant recognition: The ability to recognize large amounts of variation in the shapes of letters

  不变识别 ：识别字母形状中大量变化的能力

• Segmentation: The ability to separate one letter from the other

  细分 ：能够将一个字母与另一个字母分开

• Context: The ability to holistically understand the CAPTCHA to identify individual characters.

  上下文 ：全面理解CAPTCHA以识别单个字符的能力。

On their own, each of these poses a significant challenge for a computer. Together, they make the CAPTCHA very hard to solve. Variations include simple math problems where you are required to read a distorted image containing a simple math problem and input the answer, time-based CAPTCHAs where you are asked to fill a form and the time taken is recorded, etc.

它们本身对计算机构成了重大挑战。 在一起，它们使验证码很难解决。 变化包括简单的数学问题，需要您阅读包含简单的数学问题的失真图像并输入答案，基于时间的验证码，要求您填写表格并记录所花费的时间，等等。

Picture-based CAPTCHAs

基于图片的验证码

PiCaptcha comes from picture captcha. These ask you to identify an image or a series of images containing certain objects. They are often basic objects and quite easy for humans to identify in a few seconds. This takes advantage of computers’ weaknesses in solving vision-related and image-based problems.

PiCaptcha来自图片验证码。 这些要求您识别一个图像或包含某些对象的一系列图像。 它们通常是基本物体，很容易让人类在几秒钟内识别出来。 这利用了计算机在解决视觉相关和基于图像的问题方面的弱点。

No Captcha CAPTCHAs

没有验证码验证码

This is the simplest form of a CAPTCHA, at least for the user to solve. It usually just contains the text “I’m not a robot” with a checkbox. Checking this box is sufficient to prove your humanity. What goes on behind the scenes however is a little more complicated. The CAPTCHA examines cues the user unwittingly provides, including mouse movements to click the checkbox, the coordinates of the checkbox they click on, how long they hover on the checkbox, and other variables that are kept secret to prevent bot makers from trying to circumvent them. The entire behavior model is then used to determine if a user is human or a bot.

这是CAPTCHA的最简单形式，至少需要用户解决。 它通常仅包含带有复选框的文本“我不是机器人”。 选中此框足以证明您的人格。 但是，幕后发生的事情要复杂一些。 验证码会检查用户不经意间提供的提示，包括鼠标移动以单击复选框，他们单击的复选框的坐标，将鼠标悬停在复选框上的时间以及其他秘密变量，以防止机器人制造商试图绕过它们。 然后使用整个行为模型来确定用户是人类还是机器人。

The future of CAPTCHAs

验证码的未来

A quick Google search on the phrase “CAPTCHA solver” will return an abundance of options, showing that CAPTCHAs may be hard to solve for computers, but they are not impossible. To keep bots out without significantly affecting the user’s browsing experience, CAPTCHAs are going to have to stay one step ahead. This will include better user behavioral pattern models to tell a human from a bot, probably even without explicitly asking. Another way would be the use of biometrics from a smartphone, ranging from Face ID to fingerprints. Data from smartphones accelerometer, gyroscope, and other sensors can also be leveraged to determine if an attempted action came from a human or a bot.

Google对短语“ CAPTCHA求解器”的快速搜索将返回大量选项，表明验证码可能很难用计算机来求解，但并非不可能。 为了使漫游器保持不影响用户浏览体验的状态，验证码必须保持领先地位。 这将包括更好的用户行为模式模型，甚至可以在没有明确询问的情况下，通过机器人告诉人类。 另一种方法是使用智能手机中的生物识别技术，包括Face ID到指纹。 来自智能手机的加速度计，陀螺仪和其他传感器的数据也可以用于确定尝试的动作是来自人类还是机器人。

So next time one of those widgets popup asking you to prove your humanity, think of it this way; you are doing a good deed to humanity and helping keep the internet safe by keeping malicious bots out. I hope this article has been informative on why we have CAPTCHAs and if you have any thoughts on other ways to tell humans and bots apart, please leave a response below.

因此，下一次这些小部件弹出窗口要求您证明自己的人性时，请以这种方式思考； 您正在为人类做好事，并通过阻止恶意机器人程序来帮助确保互联网安全。 我希望本文能够为我们提供为何使用验证码提供有益的信息，如果您对区分人类和机器人的其他方式有任何想法，请在下面留下回复。