captcha | 易学教程

SimpleCaptcha and wav playback

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问题 Our client is using SimpleCaptcha. My understanding is that SimpleCaptcha is able to produce audio captchas in WAVE format (.wav). Later these CAPTCHA-s are played back using the HTML5 audio tag, something like this: <audio controls="controls" autoplay> <source src="captcha.wav" /> </audio> Of course this is not cross browser compatible and one of the reasons is the WAVE format. This link suggests that IE9 supports only MP3 while most other browsers are fine with OGG and WAVE. Further MP3 is

Time to crack DES? Is it a task suitable for a script kiddie yet?

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Already understanding that AES is the encryption method of choice, should existing code that uses DES be re-written if the likely threat is on the level of script kiddies? (e.g. pkzip passwords can be cracked with free utilities by non-computer professionals, so is DES like that?) A quick google search seems to imply that even deprecated DES still requires a super computer and large quantity of time--or have times changed? In particular, this CAPTCHA library uses DES to encrypt the challenge string which is sent to the user in viewstate. DES is broken so far as storing sensitive data, and so I

Use AJAX to reload captcha

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问题 This question may have been asked already - but unfortunately, I could not find any satisfactory answers. I will just ask it for my concrete case and ask the admins not to delete the question for at least a few days so I can try it out... I have a page. It uses a captcha. Like so: <?php session_start(); // the captcha saves the md5 into the session ?> <img src="captcha.php" onclick="this.src = this.src" /> That was my first code. It did not work, because the browser condsidered it useless to

Stopping spammers from creating accounts (reCaptcha not doing the trick)

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问题 Hi we have just noticed a bunch of Nigerian spam accounts in our email system. Now, we do have a reCaptcha in the signup form but apparently they circumvent it, manually or otherwise. It seems like a semi-manual circumvention since the accounts aren't created in bulk but instead as a steady stream with a few minutes in between. Since most of the spam accounts were created by IP addresses from Nigeria, we have just set up some simple IP filters over a couple of pretty broad IP ranges and that

PHP: Reloading the captcha image from javascript

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I have a user registration form in PHP .I put captcha image check in the page.I used it like this <img src="captcha.php" alt="Enter this text in the adjacent text box" id="imgCaptcha" /> and in my javascript i will validate this with the same number which is generated in the image (from captcha.php page) . That number was set in a session variable too. Now i want to reload the image to another image from my javascript , if the validattion fails .Is there any way to do so ? In my captcha.php page,I am creating a Number randomly and then creating an image using imagejpeg. I set this number (in

Open Source Invisible reCAPTCHA alternatives [closed]

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问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed last year . 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)? 回答1: SecurImage or phpcaptcha is open source alternative to Google reCaptcha v2. But I don't think there's any alternative to the Invisible reCaptcha yet. You can refer to

How do I correctly Re-render a Recaptcha in ASP.NET MVC 2 after an AJAX POST

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Ok... I've downloaded and implemented this Recaptcha implementation for MVC which uses the ModelState to confirm the validity of the captcha control. It works brilliantly... except when I start to use it in an AJAX Form. In a nutshell, when a div is re-rendered with AJAX, the ReCaptcha that it should contain does not appear, even though the relevant <scripts> are in the source after the partial render. Code Below. using (Ajax.BeginForm("CreateComment", "Blog", new AjaxOptions() { HttpMethod = "POST", UpdateTargetId = "CommentAdd", OnComplete="ReloadRecaptcha", OnSuccess = "ShowComment",

CodeIgniter CAPTCHA validation

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I have created some form for inserting data into database and for checking if the data was sent from human I have used CAPTCHA which is already integrated to CI. This is my controller: $checkrules = array( 'img_path' => realpath(APPPATH . '../upload/checking/img') . '/', 'img_url' => base_url() . 'upload/checking/img/', 'font_path' => realpath(APPPATH . '../upload/checking/font.ttf'), 'img_width' => 150, 'img_height' => 30, 'expiration' => 7200 ); $check = create_captcha($checkrules); $data['checkimg'] = $check['image']; $this->form_validation->set_rules('name', 'Name', 'required|max_length[40

Client Server REST API captcha implementation

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问题 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 of captcha implementation in this case? Captcha would be used for user registration etc. I'm not limited to any specific libraries, only requirement is that there cannot be any calls to 3rd party servers on client side (js libraries hosted on 3rd party servers or req api key etc). thanks 回答1: When

Is it immoral to put a captcha on a login form?

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问题 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 inapropiate for that purpose, and that it was quite exotic to see a captcha in that place. I've seen captcha images on signup, contact, password recovery forms, etc. So I personally don't see inapropiate to put a captcha also on a place like that. Well, it obviously burns down usability a little bit,