Please ask for a more secure verification code, thank you

Ask for a more secure verification code, thank you
This post was last edited by allen_studies on 2013-01-23 16:56:44

What font is the letter? This adhesion effect is good-looking, does not affect user input, but also more secure?
Has anyone studied this writing, seeking source code ...

Or is there a better and more secure CAPTCHA recommendation? Thank you

In addition, I just looked at Baidu's verification code, found that each request before the server to get a similar key thing, and then take this key request will appear different verification code, otherwise constantly request, return is the same verification code.
What is the general purpose of this practice to prevent? Does it seem useless to prevent someone from deliberately collecting a special code library?

------Solution--------------------
The security of the verification code is related to the ability of OCR-the relationship between Spear and shield
It is clear that complexity –
Traditional Kanji > Simplified Chinese characters > Korean > Japanese > Other symbols > English > Arabic numerals (with other words, not mentioned here)
Different fonts, distortions, and interferences increase the complexity, or even the level, of course, each of which involves the client's understanding of the input problem.
Because GBK or Big5 all contain simple and complex words, so the OCR does well, the complexity of the Jianfan difference will not be

can also be combined with the "think" verification, so that the answer does not appear in the verification code (more confused is # Two questions I will not answer)
This shows the more complex, the customer experience is also worse, customer gain and loss so still need to consider carefully
Especially for mobile users, it is best to reduce input as much as possible
Any increase in the difficulty, the loss of potential customers must be more than the malicious submission of interception, but the fixed customer is not lost, if you think casually discard some normal visitors (prospects) do not so-called do it


------Solution--------------------
Google Open Source Search Captcha

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