aeyoll

<p>Pow Captcha is a WordPress plugin that adds Proof of Work (PoW) captcha verification to your forms. This provides an effective way to prevent spam and bot submissions without requiring users to solve visual puzzles or complete complex challenges.</p>
<p>The plugin integrates seamlessly with popular form plugins including:</p>
<ul>
<li>Contact Form 7</li>
<li>Gravity Forms</li>
<li>And more coming soon</li>
</ul>
<p>Features:</p>
<ul>
<li>Lightweight and fast</li>
<li>No visual puzzles for users</li>
<li>Effective spam protection</li>
<li>Easy integration with existing forms</li>
<li>Customizable difficulty levels</li>
<li>Developer-friendly with hooks and filters</li>
</ul>
<h3>WP-CLI commands</h3>
<h3>Configure the plugin</h3>
<p>wp pow-captcha set_api_key “your-secret-api-key”<br />
wp pow-captcha set_api_url “https://your-captcha-service.com”<br />
wp pow-captcha set_enable_on_login_form true</p>
<h3>Check configuration</h3>
<p>wp pow-captcha status</p>
<h3>Clear cache when needed</h3>
<p>wp pow-captcha clear_cache</p>


Pow Captcha

Adds Pow Captcha verification to forms to prevent spam and bot submissions.

Takayuki Miyoshi

<p>Really Simple CAPTCHA does not work alone and is intended to work with other plugins. It is originally created for <a href="https://contactform7.com/" rel="nofollow ugc">Contact Form 7</a>, however, you can use it with your own plugin.</p>
<p>Note: This product is “really simple” as its name suggests, i.e., it is not strongly secure. If you need perfect security, you should try other solutions.</p>
<h4>How does it work?</h4>
<p>Really Simple CAPTCHA does not use PHP “Sessions” for storing states, unlike many other PHP CAPTCHA solutions, but stores them as temporary files. This allows you to embed it into WordPress without worrying about conflicts.</p>
<p>When you generate a CAPTCHA, Really Simple CAPTCHA creates two files for it; one is an image file of CAPTCHA, and the other is a text file which stores the correct answer to the CAPTCHA.</p>
<p>The two files have the same (random) prefix in their file names, for example, “a7hk3ux8p.png” and “a7hk3ux8p.txt.” In this case, for example, when the respondent answers “K5GF” as an answer to the “a7hk3ux8p.png” image, then Really Simple CAPTCHA calculates hash of “K5GF” and tests it against the hash stored in the “a7hk3ux8p.txt” file. If the two match, the answer is confirmed as correct.</p>
<h4>How to use with your plugin</h4>
<p>Note: Below are instructions for plugin developers.</p>
<p>First, create an instance of ReallySimpleCaptcha class:</p>
<pre><code>$captcha_instance = new ReallySimpleCaptcha();
</code></pre>
<p>You can change the instance variables as you wish.</p>
<pre><code>// Change the background color of CAPTCHA image to black
$captcha_instance->bg = array( 0, 0, 0 );
</code></pre>
<p>See really-simple-captcha.php if you are interested in other variables.</p>
<p>Generate a random word for CAPTCHA.</p>
<pre><code>$word = $captcha_instance->generate_random_word();
</code></pre>
<p>Generate an image file and a corresponding text file in the temporary directory.</p>
<pre><code>$prefix = wp_rand();
$captcha_instance->generate_image( $prefix, $word );
</code></pre>
<p>Then, show the image and get an answer from respondent.</p>
<p>Check the correctness of the answer.</p>
<pre><code>$correct = $captcha_instance->check( $prefix, $the_answer_from_respondent );
</code></pre>
<p>If the $correct is true, go ahead. Otherwise, block the respondent — as it would appear not to be human.</p>
<p>And last, remove the temporary image and text files, as they are no longer in use.</p>
<pre><code>$captcha_instance->remove( $prefix );
</code></pre>
<p>That’s all.</p>
<p>If you wish to see a live sample of this, you can try <a href="https://contactform7.com/captcha/" rel="nofollow ugc">Contact Form 7</a>.</p>


Really Simple CAPTCHA

Needed this for an installation with custom forms. I used the plugin developers instructions and was able to make a fully custom implementation based on server side validation within 30 minutes. No more spam bots misusing the forms. Thank you!

Great work - easy to implement

Really Simple CAPTCHA is a CAPTCHA module intended to be called from other plugins. It is originally created for my Contact Form 7 plugin.

Pow Captcha vs Really Simple CAPTCHA