Questions tagged [captcha]

Completely Automated Public Turing test to tell Computers and Humans Apart used in form validation to restrict access to humans only

127 questions
29
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3 answers

Is there anything insecure about Google ReCaptcha?

In this question on software recommendations, the OP asks for an alternative to Google reCAPTCHA because "for a security reasons also we don't want to depend on any out side services". As far as I know, you ask Google for a CAPTCHA, you display it,…
23
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3 answers

If we know CAPTCHA can be beat, why are we still using them?

If we know CAPTCHA can be beat, why are we still using them? A 35% to 90% success rate like wikipedia is stating means software is better at solving CAPTCHAs then I am.
sup
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13
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AntiForgeryToken versus Captcha

I am having some question regarding captcha and AntiForgeryToken Do I need to use captcha if I am using AntiForgeryToken in an MVC application. Does AntiForgeryToken prevents automated form submission? Can I use AntiForgeryToken as an alternative…
Twix
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9
votes
5 answers

What type of captcha will you recommend?

What type of captcha will you recommend? I am looking mainly at usability, ease of use (development too), relatively secure Usability I find that those captcha with very curly words/numbers are sometimes too unreadable. What I start to see in many…
jiewmeng
5
votes
5 answers

Why re-verify with CAPTCHA on failed form entry?

Is there a reason for sites to ask for another CAPTCHA verification when some other part of the registration form, e.g. the username, was invalid?
user1633
4
votes
2 answers

Are photo recognition captchas a reliable way to distinguish humans from bots?

You all know captchas that require you to either type some letters displayed in an obfuscated way as image. Recently I started to see more and more captchas that show you a set of small photos and require you to e.g. "select all street signs" or…
Byte Commander
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Are captchas based on ASCII art secure enough?

I have just came across an ASCII art captcha, something that I have never seen before. It seems to be really easy to implement server side! Are ASCII art captchas secure enough?
Renato Gama
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5 answers

Anyone using Asirra in production? Are there similar alternatives?

The Asirra project is a Captcha alternative that shows you pictures of kittens and puppies to fend off bots and prove that the end user is a human. Is anyone using Asirra (or something similar) in production? What alternatives are you aware…
makerofthings7
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1 answer

A potential CAPTCHA phishing attack against reCAPTCHA?

In reCAPTCHA's API (without plugin), the key part is