Questions tagged [captcha]
Captcha is a type of challenge-response test used in computing as an attempt to ensure that the response is given by a human being and not generated by a computer.
captcha
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How does Google reCAPTCHA v2 work behind the scenes?
This post refers to Google ReCaptcha v2 (not the latest version)
Recently Google introduced a simplified "captcha" verification system (video) that enables users to pass the "captcha" just by ...
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317
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103
answers
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Practical non-image based CAPTCHA approaches?
It looks like we'll be adding CAPTCHA support to Stack Overflow. This is necessary to prevent bots, spammers, and other malicious scripted activity. We only want human beings to post or edit things ...
175
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14
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Has reCaptcha been cracked / hacked / OCR'd / defeated / broken? [closed]
Have any programming methods have been used to defeat reCAPTCHA?
I'm interested in seeing evidence and potentially demonstrations that reCAPTCHA in particular has been made obsolete by completely ...
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votes
23
answers
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ReCaptcha API v2 Styling
I have not had much success finding how to style Google's new recaptcha (v2). The eventual goal is to make it responsive, but I am having difficulty applying styling for even simple things like width.
...
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How do I show multiple recaptchas on a single page?
I have 2 forms on a single page. One of the forms has a Recaptcha displaying all the time. The other should display a Recaptcha only after a certain event such as maxing out login attempts. So ...
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82
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2
answers
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ReCaptcha 2.0: enable Submit button on callback if recaptcha successful
I have a very simple form as follows. I want to make it so that the Submit button is disabled, and only enabled after the user has successfully completed the ReCaptcha.
I'm assuming I'm going to need ...
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votes
6
answers
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Recommendations for java captcha libraries [closed]
I'm looking for a replacement for JCaptcha, which doesn't seem to be maintained any more, and isn't very good to begin with. The replacement has to integrate nicely with JavaEE webapps.
As I can see ...
60
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6
answers
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How can I bypass the Google CAPTCHA with Selenium and Python?
How can I bypass the Google CAPTCHA using Selenium and Python?
When I try to scrape something, Google give me a CAPTCHA. Can I bypass the Google CAPTCHA with Selenium Python?
As an example, it's ...
user11960891
50
votes
18
answers
21k
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Blocking comment spam without using captcha [closed]
What are some non-captcha methods for blocking spam on my comments?
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16
answers
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How can I avoid google mail server asking me to log in via browser?
I am trying to send emails from Django using an email configured by Google Apps, my configuration at the settings.py file looks something like this:
EMAIL_HOST = 'smtp.gmail.com'
EMAIL_HOST_USER = '...
41
votes
3
answers
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HTTP Status Code for Captcha
Sometimes (when the resource is requested too often) I'm intercepting the presentation of a (HTML) resource with a captcha. The interception doesn't produce any redirection. It happens all at the same ...
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Recaptcha creates iFrame on page, breaks styling
Recaptcha is adding a "This frame prevents back/forward cache problems in Safari" iFrame to the top of my website (code included below), which is pushing off the styling by 20-30px (approximately).
...
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36
votes
1
answer
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Vkontakte API using OAuth does not work with Captcha
Vkontakte API rejects requests with Captcha. Here is the example what I do.
After the third request I get:
Captcha error (14) - Captcha needed.
According to documentation it's sufficient to add ...
- 561
29
votes
3
answers
16k
views
Easy-to-use django captcha or registration app with captcha? [closed]
I want to implement user registration using captcha in Django.
The workflow of django-registration app is a great, but it doesn't have captcha.
What captcha would you recommend to use with it?
Are ...
- 1,299
26
votes
27
answers
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26
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7
answers
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Recommendations for a captcha on Ruby on Rails [closed]
I'd like to implement a captcha in a Rails project for a form submission, but I'm not sure what to go with. I'm inclining towards simplicity of implemention, and reliability when in use, over it being ...
- 1,087
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2
answers
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rails - Choosing captcha plugin [closed]
There are a lot of captchas plugins in Rails and also many types of solutions for preventing spamming and flooding. So it isn't only Rails question.
Let's see what types of plugins do we have:
1. ...
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25
votes
9
answers
24k
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Stop spam without captcha
I want to stop spammers from using my site. But I find CAPTCHA very annoying. I am not just talking about the "type the text" type, but anything that requires the user to waste his time to prove ...
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5
answers
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New Google reCaptcha: How to change text "I'm not a robot"
I've installed the latest Google reCaptcha tool on our yoga website. Now the users are confused about the text "I'm not a robot" that appears next to the checkbox.
Most of our users do not know what ...
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votes
3
answers
25k
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Open Source Invisible reCAPTCHA alternatives [closed]
Is there any close or best open source solutions as Google's Invisible reCAPTCHA V2? And also as Google's regular reCAPTCHA V2(checkbox one)?
- 463
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8
answers
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Best way to limit (and record) login attempts
Obviously some sort of mechanism for limiting login attempts is a security requisite. While I like the concept of an exponentially increasing time between attempts, what I'm not sure of storing the ...
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24
votes
4
answers
8k
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reCAPTCHA accepting one word out of two
I am a bit confused about how reCAPTCHA works. I have implemented it
using ROR.
Sometimes even if i specify only one word out of two, it returns true
while sometimes it fails.
I am really confused ...
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22
votes
6
answers
11k
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Is it immoral to put a captcha on a login form?
In a recent project I put a captcha test on a login form, in order to stop possible brute force attacks.
The immediate reaction of other coworkers was a request to remove it, saying that it was ...
22
votes
4
answers
57k
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How to deal with the captcha when doing Web Scraping in Puppeteer?
I'm using Puppeteer for Web Scraping and I have just noticed that sometimes, the website I'm trying to scrape asks for a captcha due to the amount of visits I'm doing from my computer. The captcha ...
user10021033
22
votes
3
answers
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Cleaning up captcha image
I'm trying to clean up the image above I've tried several different methods using open cv, I either erode the original image too much to the point where parts of the letters become missing such as ...
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4
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Difference between CAPTCHA and reCAPTCHA
What are the differences between CAPTCHA and reCAPTCHA?
What is the best situation to opt for reCAPTCHA?
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1
answer
6k
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Detect when reCaptcha does not load
What is the best way to detect if a reCaptcha v2 does not load? I would like to alert users when they need to use the captcha to continue, but it was unable to load.
- 1,837
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2
answers
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How to Use Captcha in asp.net mvc [closed]
can any one tell me how to use captcha in asp.net mvc?
is there any need to download any control for it?
- 431
21
votes
5
answers
3k
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Is there an Unobtrusive Captcha for web forms?
What is the best unobtrusive CAPTCHA for web forms? One that does not involve a UI, rather a non-UI Turing test. I have seen a simple example of a non UI CAPTCHA like the Nobot control from Microsoft....
- 2,158
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votes
6
answers
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What is a good invisible captcha? [closed]
What is a good invisible captcha? My site requires JavaScript so anything which requires that is fine.
20
votes
1
answer
10k
views
Qaptcha - is it effective?
See the demo of JQuery Qaptcha here - http://www.myjqueryplugins.com/QapTcha/demo
It requires you to slide the slider to unlock and prove you're human. I've read all about how it's setting random ...
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1
answer
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How do I set up Scrapy to deal with a captcha
I'm trying to scrape a site that requires the user to enter the search value and a captcha. I've got an optical character recognition (OCR) routine for the captcha that succeeds about 33% of the time. ...
- 381
19
votes
8
answers
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What is the best/recommended CAPTCHA component for ASP.NET [closed]
Does anyone have any recommendations for CAPTCHA components for use in ASP.NET projects?
- 1,191
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3
answers
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Client Server REST API captcha implementation
I'm building client server REST application.
Client side is based on Angular while server is PHP (not that it matters much anyhow).
What I am wondering if there are any best practices, good examples ...
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8
answers
6k
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How to unit test a form with a captcha field in django?
I would like to unit test a django view by sumitting a form. The problem is that this form has a captcha field (based on django-simple-captcha).
from django import forms
from captcha.fields import ...
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Will an English CAPTCHA be an issue for people in other countries?
What if I have a captcha that displays a series of English characters. Will people who don't speak English have trouble interpreting and/or typing these characters? If this is the case then what is ...
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15
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Most effective form of CAPTCHA?
Of all the forms of CAPTCHA available, which one is the "least crackable" while remaining fairly human readable?
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How to use Python plugin reCaptcha client for validation?
I want to make a captcha validation.
I get the key from the recaptcha website and already succeed to put the public key to load the webpage with the challenge.
<script type="text/javascript"
...
- 6,909
16
votes
4
answers
12k
views
What CAPTCHA system is compatible with ASP.NET MVC? [closed]
What CAPTCHA system is compatible with ASP.NET MVC? Are there any good examples out there?
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6
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How CURL Login with Captcha and Session
define('COOKIE', './cookie.txt');
define('MYURL', 'https://register.pandi.or.id/main');
function getUrl($url, $method='', $vars='', $open=false) {
$agents = 'Mozilla/5.0 (X11; U; Linux i686; en-...
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answers
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views
How do I add a CAPTCHA to my PHP form?
My knowledge of php is not good and I need help.
I have this php form but I don't know how to add a CAPTCHA mechanism.
How do I achieve this?
- 171
16
votes
4
answers
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Integrating Captcha with Spring Security
What is appropriate way to integrate SpringSecurity with Capcha ?
I have following use case :
When user will tries to login, if we he failed to login N times, captcha will be displayed, so ...
- 380
16
votes
2
answers
2k
views
New Google reCAPTCHA JavaScript namespace callback
We're trying to implement the new Google reCAPTCHA on our website, however when we try and load a callback from it using a namespaced function, the callback does not run.
Changing the callback to ...
- 1,661
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3
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How could we integrate the Captcha in iOS application?
I googled for integration of Captcha in iOS app but do not found any relevant way to do so. Even i sign up with reCAPTCHA and searched whether the plugins for Captcha are available for iOS or not? I ...
- 1,625
16
votes
1
answer
936
views
reCAPTCHA triggering Java warning in IE
We recently added reCAPTCHA 2.0 to our site and now we're occasionally getting a message from IE about Java. Here is the message:
The page you are viewing uses Java. More information on Java ...
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15
votes
2
answers
14k
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Google reCAPTCHA fail for second time submit
I implement the reCAPTCHA in this tutorial,
https://codeforgeek.com/2014/12/google-recaptcha-tutorial/
which work well for the first time submit. The problems I have are:
I send the captcha with ...
- 1,991
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votes
4
answers
78k
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Is there any possible ways to bypass cloudflare security checks?
We all know, sometimes cloudflare like to check their client visitor to make sure that the visitor isn't a real human. The security check require us to pass Google Recaptcha. What i want to ask is it ...
- 1,322
14
votes
4
answers
35k
views
CAPTCHA in java [duplicate]
I wanna give a shot at developing a secure login system in Java. How should I implement CAPTCHA using Java?
- 2,941
14
votes
1
answer
21k
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Howto additionally add Spring Security captcha filter for specific urls only
I am looking for a non invasive way to add a captcha filter for certain api calls.
My setup consists of two WebSecurityConfigurerAdapters with one filter each (not the captcha filter):
Internal api (...
- 2,494
13
votes
7
answers
28k
views
How to reset Google recaptcha with react-google-recaptcha
Looks like the google recaptcha works in such a way that if a verification attempt has been made with a particular token, it cannot be used again.
Docs states that "you will need to call ...
- 667