What Does Captcha Required Mean
What Does CAPTCHA Mean? | CAPTCHA Types & Examples
What is CAPTCHA
CAPTCHA stands for the Completely Automated Public Turing test to tell Computers and Humans Apart. CAPTCHAs are tools you can use to differentiate between real users and automated users, such as bots. CAPTCHAs provide challenges that are difficult for computers to perform but relatively easy for humans. For example, identifying stretched letters or numbers, or clicking in a specific area.
What are CAPTCHAs Used for
CAPTCHAs are used by any website that wishes to restrict usage by bots. Specific uses include:
Maintaining poll accuracy—CAPTCHAs can prevent poll skewing by ensuring that each vote is entered by a human. Although this does not limit the overall number of votes that can be made, it makes the time required for each vote longer, discouraging multiple votes.
Limiting registration for services—services can use CAPTCHAs to prevent bots from spamming registration systems to create fake accounts. Restricting account creation prevents waste of a service’s resources and reduces opportunities for fraud.
Preventing ticket inflation—ticketing systems can use CAPTCHA to limit scalpers from purchasing large numbers of tickets for resale. It can also be used to prevent false registrations to free events.
Preventing false comments—CAPTCHAs can prevent bots from spamming message boards, contact forms, or review sites. The extra step required by a CAPTCHA can also play a role in reducing online harassment through inconvenience.
How Does CAPTCHA Work
CAPTCHAs work by providing information to a user for interpretation. Traditional CAPTCHAs provided distorted or overlapping letters and numbers that a user then has to submit via a form field. The distortion of the letters made it difficult for bots to interpret the text and prevented access until the characters were verified.
This CAPTCHA type relies on a human’s ability to generalize and recognize novel patterns based on variable past experience. In contrast, bots can often only follow set patterns or input randomized characters. This limitation makes it unlikely that bots will correctly guess the right combination.
Since CAPTCHA was introduced, bots that use machine learning have been developed. These bots are better able to identify traditional CAPTCHAs with algorithms trained in pattern recognition. Due to this development, newer CAPTCHA methods are based on more complex tests. For example, reCAPTCHA requires clicking in a specific area and waiting until a timer runs out.
Drawbacks of Using CAPTCHA
The overwhelming benefit of CAPTCHA is that it is highly effective against all but the most sophisticated bad bots. However, CAPTCHA mechanisms can negatively affect the user experience on your website:
Disruptive and frustrating for users
May be difficult to understand or use for some audiences
Some CAPTCHA types do not support all browsers
Some CAPTCHA types are not accessible to users who view a website using screen readers or assistive devices
CAPTCHA Types: Examples
Modern CAPTCHAs fall into three main categories—text-based, image-based, and audio.
Text-based CAPTCHAs are the original way in which humans were verified. These CAPTCHAs can use known words or phrases, or random combinations of digits and letters. Some text-based CAPTCHAs also include variations in capitalization.
The CAPTCHA presents these characters in a way that is alienated and requires interpretation. Alienation can involve scaling, rotation, distorting characters. It can also involve overlapping characters with graphic elements such as color, background noise, lines, arcs, or dots. This alienation provides protection against bots with insufficient text recognition algorithms but can also be difficult for humans to interpret.
Text-based CAPTCHA patterns
Techniques for creating text-based CAPTCHAs include:
Gimpy—chooses an arbitrary number of words from an 850-word dictionary and provides those words in a distorted fashion.
EZ-Gimpy—is a variation of Gimpy that uses only one word.
Gimpy-r—selects random letters, then distorts and adds background noise to characters.
Simard’s HIP—selects random letters and numbers, then distorts characters with arcs and colors.
Image-based CAPTCHAs were developed to replace text-based ones. These CAPTCHAs use recognizable graphical elements, such as photos of animals, shapes, or scenes. Typically, image-based CAPTCHAs require users to select images matching a theme or to identify images that don’t fit.
You can see an example of this type of CAPTCHA below. Note that it defines the theme using an image instead of text.
Example of image-based CAPTCHA
Image-based CAPTCHAs are typically easier for humans to interpret than text-based. However, these tools present distinct accessibility issues for visually impaired users. For bots, image-based CAPTCHAs are more difficult than text to interpret because these tools require both image recognition and semantic classification.
Audio CAPTCHAs were developed as an alternative that grants accessibility to visually impaired users. These CAPTCHAs are often used in combination with text or image-based CAPTCHAs. Audio CAPTCHAs present an audio recording of a series of letters or numbers which a user then enters.
These CAPTCHAs rely on bots not being able to distinguish relevant characters from background noise. Like text-based CAPTCHAs, these tools can be difficult for humans to interpret as well as for bots.
Math or Word Problems
Some CAPTCHA mechanisms ask users to solve a simple mathematical problem such as “3+4” or “18-3”. The assumption is that a bot will find it difficult to identify the question and devise a response. Another variant is a word problem, asking the user to type the missing word in a sentence, or complete a sequence of several related terms. These types of problems are accessible to vision impaired users, but at the same time they may be easier for bad bots to solve.
Social Media Sign In
A popular alternative to CAPTCHA is requiring users to sign in using a social profile such as Facebook, Google or LinkedIn. The user’s details will be automatically filled in using single sign on (SSO) functionality provided by the social media website.
This is still disruptive, but may actually be easier for the user to complete than other forms of CAPTCHA. An additional benefit is that it is a convenient registration mechanism.
No CAPTCHA ReCAPTCHA
This type of CAPTCHA, known for its use by Google, is much easier for users than most other types. It provides a checkbox saying “I am not a robot” which users need to select – and that’s all. It works by tracking user movements and identifying if the click and other user activity on the page resembles human activity or a bot. If the test fails, reCAPTCHA provides a traditional image selection CAPTCHA, but in most cases the checkbox test suffices to validate the user.
Imperva Bot Detection: CAPTCHA as a Last Line of Defense
Imperva provides the option to deploy CAPTCHAs, but uses it as the final line of defense, if all other bot identification mechanisms fail. This means it will be used for a very small percentage of user traffic. Imperva does provide the option to manually enforce CAPTCHA, for websites that need a stricter approach to advanced bot protection.
In addition to providing bad bot mitigation, Imperva provides multi-layered protection to make sure websites and applications are available, easily accessible and safe. The Imperva application security solution includes:
DDoS Protection—maintain uptime in all situations. Prevent any type of DDoS attack, of any size, from preventing access to your website and network infrastructure.
CDN—enhance website performance and reduce bandwidth costs with a CDN designed for developers. Cache static resources at the edge while accelerating APIs and dynamic websites.
Cloud WAF—permit legitimate traffic and prevent bad traffic. Safeguard your applications at the edge with an enterprise‑class cloud WAF.
Gateway WAF—keep applications and APIs inside your network safe with Imperva Gateway WAF.
RASP—keep your applications safe from within against known and zero‑day attacks. Fast and accurate protection with no signature or learning mode.
FIX: reCAPTCHA not working in Chrome, Firefox, or any browser
reCAPTCHA is a free Google service to confirm that a system is being used by a human being and not a robot or bot. It helps websites secure themselves against malicious automated tools and spam attacks. It is similar to Captcha, the only difference is that Captcha asks you to solve some puzzles to make sure you are not a robot. And, reCAPTCHA asks you to tick an I’m not a Robot button to confirm your, multiple users have reported that reCAPTCHA is not working in their web browser. Many of them have told that it appears initially and then fades away when you click on it. And when you refresh the web page, it shows you a warning message such as verification failed, your computer is sending automated queries, you are also encountering the same issue in your web browser, check out this article. Here, I am going to mention solutions to fix the reCAPTCHA not working in the browser issue. But before that, let us try to understand what causes this asons that cause reCAPTCHA not working issue in browserIf reCAPTCHA is not working in your browser, then this issue may arise due to several reasons that include:You are using an older version of your web or proxy service is interrupting with browser is infected with malware like a browser hijacker, trojan, adware tool, may be triggered due to the browser profile; consider creating a new browser may experience this error if your IP address is detected as can try fixing the reCAPTCHA not working issue using various methods that I am going to share in this article. Let’s get straight to the solutions are the ways to resolve reCAPTCHA not working error in your browser. But before you begin, you might want to clear your browser cache first and your web browser to its latest versionDisable your VPN or Proxy ServiceReset IP for malware on your PCReset your browser1] Update your web browser to its latest versionAs one of the most common reasons that lead to the “reCAPTCHA not working” issue is outdated browser version, you should get it updated. Here, I am going to mention steps to update two widely used web browsers that include Google Chrome and Mozilla Google ChromeLaunch Google Chrome and go to the three-dot, click on the Help > About Chrome will now search for the latest update automatically and install updating Chrome, restart it and go to the reCAPTCHA site to see if it is working fine Mozilla FirefoxOpen Firefox, go to its three-bar menu and click on the Help, tap on the About Firefox option. It will check and download updates which you can install by clicking the Update launch Firefox and open the reCAPTCHA window and check if the issue is gone. 2] Disable your VPN or Proxy ServiceA VPN service might be causing the reCAPTCHA not working error in your browser. Hence, try disabling the VPN application you use for some time and check if reCAPTCHA starts working in your browser. If it does, your VPN was the one causing the a similar way, disable proxy service if you use one and see if the reCAPTCHA not working problem still persists. 3] Reset IP addressIn an unfortunate case where your IP address has a negative reputation and is detected as suspicious, resetting your IP address may help you resolve this issue. This solution seems to work when reCAPTCHA is not working in any of your web browsers. Here are the steps to reset the IP address on your Windows 10 PC:Firstly, open CMD with administrator privilege; for that, search for CMD and open the app using the Run as administrator, enter the following commands one by one in CMD:netsh winsock reset
netsh int ip reset
When all the above commands are completely executed, restart your web browser and visit the reCAPTCHA page to see if it is working fine now. 4] Check for malware on your PCYou might be facing this issue if your browser is infected with some kind of malware like trojan, adware, browser hijacker, etc. So, scan your PC for malware and remove it from your PC. You can use free Antivirus Software that provides you protection against doing so, uninstall your web browser completely using a free uninstaller program. Then, download the installer for your web browser from the web and reinstall it on your your browser and check if reCAPTCHA is working properly. 5] Reset your browserIf nothing works, you may need to reset your Edge, Chrome, or Firefox browser to its original default settings. Hopefully, this guide helps you fix the reCAPTCHA reCAPTCHA work on all browsers? ReCaptcha will actively look at the browser version before allowing you access. This is applicable to all browser versions, not just Chrome, Edge, you bypass CAPTCHA? In some cases, simple CAPTCHAs can be bypassed using the Optical Character Recognition (OCR) technology that recognizes the text inside images, such as scanned documents and photographs. This technology converts images containing written text into machine-readable text read: Browser extensions to Bypass or Automatically fill CAPTCHA.
How CAPTCHAs work | What does CAPTCHA mean?
What is a CAPTCHA?
A CAPTCHA test is designed to determine if an online user is really a human and not a bot. CAPTCHA is an acronym that stands for “Completely Automated Public Turing test to tell Computers and Humans Apart. ” Users often encounter CAPTCHA and reCAPTCHA tests on the Internet. Such tests are one way of managing bot activity, although the approach has its drawbacks.
Although CAPTCHAs are designed to block automated bots, CAPTCHAs are themselves automated. They’re programmed to pop up in certain places on a website, and they automatically pass or fail users.
How does a CAPTCHA work?
Classic CAPTCHAs, which are still in use on some web properties today, involve asking users to identify letters. The letters are distorted so that bots are not likely to be able to identify them. To pass the test, users have to interpret the distorted text, type the correct letters into a form field, and submit the form. If the letters don’t match, users are prompted to try again. Such tests are common in login forms, account signup forms, online polls, and e-commerce checkout pages.
The idea is that a computer program such as a bot will be unable to interpret the distorted letters, while a human being, who is used to seeing and interpreting letters in all kinds of contexts – different fonts, different handwritings, etc. – will usually be able to identify them.
The best that many bots will be able to do is input some random letters, making it statistically unlikely that they will pass the test. Thus, bots fail the test and are blocked from interacting with the website or application, while humans are able to continue using it like normal.
Advanced bots are able to use machine learning to identify these distorted letters, so these kinds of CAPTCHA tests are being replaced with more complex tests. Google reCAPTCHA has developed a number of other tests to sort out human users from bots.
What is reCAPTCHA?
reCAPTCHA is a free service Google offers as a replacement for traditional CAPTCHAs. reCAPTCHA technology was developed by researchers at Carnegie Mellon University, then acquired by Google in 2009.
reCAPTCHA is more advanced than the typical CAPTCHA tests. Like CAPTCHA, some reCAPTCHAs require users to enter images of text that computers have trouble deciphering. Unlike regular CAPTCHAs, reCAPTCHA sources the text from real-world images: pictures of street addresses, text from printed books, text from old newspapers, and so on.
Over time, Google has expanded the functionality of reCAPTCHA tests so that they no longer have to rely on the old style of identifying blurry or distorted text. Other types of reCAPTCHA tests include:
General user behavior assessment (no user interaction at all)
How does an image recognition reCAPTCHA test work?
For an image recognition reCAPTCHA test, typically users are presented with 9 or 16 square images. The images may all be from the same large image, or they may each be different. A user has to identify the images that contain certain objects, such as animals, trees, or street signs. If their response matches the responses from most other users who have submitted the same test, the answer is considered “correct” and the user passes the test.
Picking out certain objects from blurry photos is a hard problem for computers to solve. Even advanced artificial intelligence (AI) programs struggle with it – so a bot will struggle with it as well. However, a human user should be able to do this fairly easily, since humans are used to perceiving everyday objects in all kinds of contexts and situations.
How do reCAPTCHA tests with a single checkbox work?
Some reCAPTCHA tests simply prompt the user to check a box next to the statement, “I’m not a robot. ” However, the test is not the actual action of clicking the checkbox – it’s everything leading up to the checkbox click.
This reCAPTCHA test takes into account the movement of the user’s cursor as it approaches the checkbox. Even the most direct motion by a human has some amount of randomness on the microscopic level: tiny unconscious movements that bots can’t easily mimic. If the cursor’s movement contains some of this unpredictability, then the test decides that the user is probably legitimate. The reCAPTCHA also may assess the cookies stored by the browser on a user device and the device’s history in order to tell if the user is likely to be a bot.
If the test is still unable to determine whether or not the user is a human, it may present an additional challenge, such as the image recognition test described above. However, most of the time the user’s cursor movements, cookies, and device history are conclusive enough.
How does reCAPTCHA work without any user interaction?
The latest versions of reCAPTCHA are able to take a holistic look at a user’s behavior and history of interacting with content on the Internet. Most of the time, the program can decide based on those factors whether or not the user is a bot, without providing the user with a challenge to complete. If not, then the user will get a typical reCAPTCHA challenge.
What triggers a CAPTCHA test?
Some web properties just automatically have CAPTCHAs in place as a proactive defense against bots. Other times, a test may be triggered if user behavior seems to resemble a bot’s behavior: if users request webpages or click hyperlinks at a far higher rate than average, for instance.
Are CAPTCHAs and reCAPTCHAs enough for stopping malicious bots?
Some bots can get past the text CAPTCHAs on their own. Researchers have demonstrated ways to write a program that beats the image recognition CAPTCHAs as well. In addition, attackers can use click farms to beat the tests: thousands of low-paid workers solving CAPTCHAs on behalf of bots.
Besides a CAPTCHA, there need to be other strategies in place for stopping unwanted bots (such as content scraping bots, credential stuffing bots, or spam bots).
What are the drawbacks of using CAPTCHAs or reCAPTCHAs to stop bots?
Bad user experience: A CAPTCHA test can interrupt the flow of what users are trying to do, giving them a negative view of their experience on the web property, and leading to them abandoning the webpage altogether in some cases.
Not usable for visually impaired individuals: The problem with CAPTCHAs is that they rely on visual perception. This makes them nearly impossible, not just for people who are legally blind, but for anyone with seriously impaired vision.
These tests can be fooled by bots: As described above, CAPTCHAs are not fully bot-proof and shouldn’t be relied upon for bot management.
Are there alternatives to using CAPTCHAs or reCAPTCHAs?
Bot management solutions such as Cloudflare Bot Management or Super Bot Fight Mode can identify bad bots without impacting the user experience, based on the behavior of the bot. This way, bots can be mitigated without forcing users to complete CAPTCHAs.
How are CAPTCHA and reCAPTCHA related to artificial intelligence (AI) projects?
As millions of users identify hard-to-read text and pick out objects in blurry images, that data is fed into AI computer programs so that they become better at those tasks as well.
In general, computer programs struggle with identifying objects and letters in different contexts, because context can change almost infinitely in the real world. For instance, a stop sign is a red octagon with white letters reading “STOP. ” A computer program could identify a shape-and-word combination like that fairly easily. However, a stop sign in a photo may look very different from that simple description depending on context: the angle of the photo, the lighting, the weather involved, and so on.
Via machine learning, AI programs can get better at overcoming these limitations. For the stop sign example, the programmer would feed the AI program a bunch of data on what is and is not a stop sign. For this to be effective, they need lots of examples of images with stop signs and images without stop signs, and they need human users to identify them until the program has enough data to be effective at it.
reCAPTCHA helps fill this need by getting humans to identify objects and texts, which slowly provides enough data to build robust AI programs.
What is a Turing test? How are Turing tests relevant to CAPTCHA tests?
A Turing test assesses a computer’s ability to mimic human behavior. Alan Turing, an early computing pioneer, invented the concept of a Turing test in 1950. A computer program “passes” the Turing test if its performance during the test is indistinguishable from that of a human – if it acts the way that a human would act. A Turing test is not dependent on getting answers correct; it’s about how “human” the answers sound, regardless of whether they’re right or wrong.
Although it’s called a “Public Turing test, ” a CAPTCHA is really the opposite of a Turing test – it determines whether a supposedly human user is actually a computer program (a bot) or not, instead of trying to determine if a computer is human. To accomplish this, a CAPTCHA needs to assign a brief task that people tend to be good at and computers struggle with. Identifying text and images usually fits those criteria.
Frequently Asked Questions about what does captcha required mean
FIX reCAPTCHA not working in Chrome, Firefox, or any browserReasons that cause reCAPTCHA not working issue in browser. … 1] Update your web browser to its latest version. … 2] Disable your VPN or Proxy Service. … 3] Reset IP address. … 4] Check for malware on your PC. … 5] Reset your browser. … Does reCAPTCHA work on all browsers?More items…•May 19, 2021
To pass the test, users have to interpret the distorted text, type the correct letters into a form field, and submit the form. If the letters don’t match, users are prompted to try again.
CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) is a type of security measure known as challenge-response authentication. … A CAPTCHA test is made up of two simple parts: a randomly generated sequence of letters and/or numbers that appear as a distorted image, and a text box.