Takayuki Miyoshi

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.
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.
<h4>How does it work?</h4>
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.
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.
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.
<h4>How to use with your plugin</h4>
Note: Below are instructions for plugin developers.
First, create an instance of ReallySimpleCaptcha class:
<pre><code>$captcha_instance = new ReallySimpleCaptcha();
</code></pre>
You can change the instance variables as you wish.
<pre><code>// Change the background color of CAPTCHA image to black
$captcha_instance->bg = array( 0, 0, 0 );
</code></pre>
See really-simple-captcha.php if you are interested in other variables.
Generate a random word for CAPTCHA.
<pre><code>$word = $captcha_instance->generate_random_word();
</code></pre>
Generate an image file and a corresponding text file in the temporary directory.
<pre><code>$prefix = wp_rand();
$captcha_instance->generate_image( $prefix, $word );
</code></pre>
Then, show the image and get an answer from respondent.
Check the correctness of the answer.
<pre><code>$correct = $captcha_instance->check( $prefix, $the_answer_from_respondent );
</code></pre>
If the $correct is true, go ahead. Otherwise, block the respondent — as it would appear not to be human.
And last, remove the temporary image and text files, as they are no longer in use.
<pre><code>$captcha_instance->remove( $prefix );
</code></pre>
That’s all.
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>.

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.

jp-secure

You can find docs, FAQ and more detailed information on <a href="https://www.jp-secure.com/siteguard_wp_plugin_en/" rel="nofollow ugc">English Page</a> <a href="https://www.jp-secure.com/siteguard_wp_plugin/" rel="nofollow ugc">Japanese Page</a>.
Simply install the SiteGuard WP Plugin, WordPress security is improved. 
This plugin is a security plugin that specializes in the login attack of brute force, such as protection and management capabilities.
Notes
<ul>
<li>It does not support the multisite function of WordPress.</li>
<li>It only supports Apache 1.3, 2.x for Web servers.</li>
<li>To use the CAPTCHA function, the expansion library “mbstring” and “gd” should be installed on php.</li>
<li>To use the management page filter function and login page change function, “mod_rewrite” should be loaded on Apache.</li>
<li>To use the WAF Tuning Support, WAF ( SiteGuard Server Edition ) should be installed on Apache.</li>
</ul>
There are the following functions.
<ul>
<li>Admin Page IP Filter</li>
</ul>
It is the function for the protection against the attack to the management page (under wp-admin.) 
To the access from the connection source IP address which does not login to the management page, 404 (Not Found) is returned. 
At the login, the connection source IP address is recorded and the access to that page is allowed. 
The connection source IP address which does not login for more than 24 hours is sequentially deleted. 
The URL (under wp-admin) where this function is excluded can be specified.
<ul>
<li>Rename Login</li>
</ul>
It is the function to decrease the vulnerability against an illegal login attempt attack such as a brute force attack or a password list attack. 
The login page name (wp-login.php) is changed. The initial value is “login_<5 random digits>” but it can be changed to a favorite name.
<ul>
<li>CAPTCHA</li>
</ul>
It is the function to decrease the vulnerability against an illegal login attempt attack such as a brute force attack or a password list attack, 
or to receive less comment spam. For the character of CAPTCHA, hiragana and alphanumeric characters can be selected.
<ul>
<li>Login Lock</li>
</ul>
It is the function to decrease the vulnerability against an illegal login attempt attack such as a brute force attack or a password list attack. 
Especially, it is the function to prevent an automated attack. The connection source IP address the number of login failure of which reaches 
the specified number within the specified period is blocked for the specified time. 
Each user account is not locked.
<ul>
<li>Login Alert</li>
</ul>
It is the function to make it easier to notice unauthorized login. E-mail will be sent to a login user when logged in. 
If you receive an e-mail to there is no logged-in idea, please suspect unauthorized login.
<ul>
<li>Fail Once</li>
</ul>
It is the function to decrease the vulnerability against a password list attack. Even is the login input is correct, the first login must fail. 
After 5 seconds and later within 60 seconds, another correct login input make login succeed. At the first login failure, the following error message is displayed.
<ul>
<li>Disable Pingback</li>
</ul>
The pingback function is disabled and its abuse is prevented.
<ul>
<li>Block Author Query</li>
</ul>
Prevents leakage of user names due to “/?author=” access.
<ul>
<li>Updates Notify</li>
</ul>
Basic of security is that always you use the latest version. If WordPress core, plugins, and themes updates are needed , sends email to notify administrators.
<ul>
<li>WAF Tuning Support</li>
</ul>
It is the function to create the rule to avoid the false detection in WordPress (including 403 error occurrence with normal access,) 
if WAF ( SiteGuard Server Edition ) by EG Secure Solutions is installed on a Web server. WAF prevents the attack from the outside against the Web server, 
but for some WordPress or plugin functions, WAF may detect the attack which is actually not attack and block the function. 
By creating the WAF exclude rule, the WAF protection function can be activated while the false detection for the specified function is prevented.
<h4>Translate</h4>
If you have created your own language pack, or have an update of an existing one, you can send <a href="https://codex.wordpress.org/Translating_WordPress" rel="nofollow ugc">gettext PO and MO files</a> to sgdev@jp-secure.com so that We can bundle it into SiteGuard WP Plugin. You can download the latest <a href="https://plugins.svn.wordpress.org/siteguard/trunk/languages/siteguard.pot" rel="nofollow ugc">POT file</a>, and <a href="https://plugins.svn.wordpress.org/siteguard/branches/languages/" rel="nofollow ugc">PO files in each language</a>.

SiteGuard WP Plugin


誰でもユーザーを登録できるサイトを作っているのですが、ログイン保護機能を利用しています。スパムアカウントが減りました。


ログイン保護に利用しています

SiteGurad WP Plugin is the plugin specialized for the protection against the attack to the management page and login.

Really Simple CAPTCHA vs SiteGuard WP Plugin