Justin Parr

<h3>Update: 6/2015</h3>
<p>Changed e-mail token and math problem confirmation logic.  Previously, everything happened all at once, and the user would get prompted mutliple times for the math problem.<br />
Now, the user must answer the math problem first, before the e-mail token is sent.  Once the math problem is correctly answered within the session, it isn’t asked again.  The user must now enter the correct token, which results in successful registration.<br />
SPECIAL THANKS TO OLEG M. FOR HELPING ME IDENTIFY, FIX, AND TEST THE ERROR!!</p>
<h3>Update: 5/2015</h3>
<p>Added E-mail confirmation token.  Prevents registration until user enters a token sent via e-mail.</p>
<h3>Features:</h3>
<ul>
<li>Prevent users from registering, if their IP or e-mail address is listed in the “Comments” blacklist (Settings..Discussion)</li>
<li>E-mails user a 4-digit token, and requires the user to enter the token in order to register.</li>
<li>Users must solve a simple math problem (Add two one-digit numbers).</li>
<li>Places user IP address in “Website” field.</li>
</ul>
<p>This is a super-simple user registration spam countermeasure.  I searched for a plugin that was SIMPLE and EFFECTIVE.  I looked at quite a few plugins that promised the desired effect, but were either cumbersome, or included too many unneeded or unwanted features.  Likewise, there are some very simple plugins that are less-than-effective.</p>
<h3>This plugin is VERY simple:</h3>
<p>If the user’s IP or e-mail address is listed in the “Discussion” comments blacklist, it prevents the user from registering.  This functionality should really be built in to WordPress, so, you’re welcome.</p>
<p>When the user registers, they are presented with a simple math problem – adding a 3-digit number to a 1-digit number.  99% of the “user reg spam” is based on bots being able to attack the basic WordPress registration form.  By adding even a simple math problem, most bots will fail, removing your site as a target of opportunity.  Criminals go after what’s easy – if you make it slightly more difficult for them, they will go after someone else.</p>
<p>Once the user solves the math problem, they are sent a 4 digit token via e-mail, and must enter that token to continue registration.</p>
<p>Finally, knowing the location from where your users register allows you to more effectively evaluate and block the source.  This plugin adds the user’s IP address (at the time of registration)  to the “Website” field.</p>
<p>Go to http://whois.arin.net to find out who they are.  If you decide to block the IP,  add the IP address, part of the IP address, or e-mail domain to the “Discussion” comments blacklist, and ANY user registrations from an IP address matching that pattern will be blocked.</p>
<h3>Configuration</h3>
<h3>To Configure the Plugin:</h3>
<p>NOTE:  NO CONFIGURATION IS REQUIRED.  This plugin is fully-functional using the default values.</p>
<p>In the Plugins page, click “Settings” underneath the “JP User Registration Blacklist” plugin.</p>
<ul>
<li>
<p>Seed:  This value determines how the answer to the math problem is masked.  Periodically change this, to keep the spammers and criminals at bay.  The initial value is randomly-generated.</p>
</li>
<li>
<p>Failed Math Response:  Error message displayed to the user, if they fail to correctly solve the math problem.</p>
</li>
<li>
<p>Rejected IP or E-mail:  Error message displayed to the user, if their IP or e-mail is blocked.  Keep this simple and generic, to keep them from knowing why they are being blocked.</p>
</li>
<li>
<p>Form field name for math problem:  This field name contains the user’s answer to the math problem.  Periodically change this, to keep the bots away.  The initial value is randomly-generated.</p>
</li>
</ul>
<h3>To Block an IP address</h3>
<ol>
<li>In the WordPress Dashboard, go to “Settings…Discuss”</li>
<li>To block all or part of an IP address, add it on its own line to “Comments Blacklist”</li>
<li>To block all or part of an e-mail address, add it on its own line to “Comments Blacklist”</li>
<li>Click “Save”<br />
(For more details, see Examples)</li>
</ol>


JP User Registration Blacklist

Prevent User Registration Spam, and Track New User IP address

bannersky

<p>This plugin helps you avoid spam submissions from Gravity Forms, Formidable Forms, WPForms, Contact Form 7 and Forminator.</p>
<p>This is the free version and you can set it up to use a blacklist. If the field value contains / same as an item / keyword in the applied blacklist, the form submission will be blocked. It’s easy to use, you just need to create a blacklist, enable settings for the form and apply the blacklist to the form fields. You can set one or more fields to validate. Validation messages can be customized for the form.</p>
<p>The Pro version described here: https://www.bannersky.com/gravity-forms-blacklist-and-custom-validation/ can also be used as a whitelist, IP address, email or invitation code to validate visitor input. Support for blocking email domains, giving you the option to allow or block submissions instead of always allowing submissions. Supports blocking IP addresses by country or allowing only IP addresses from a certain country.</p>
<h3>Short Description</h3>
<p>This plugin helps you avoid spam submissions from Gravity Forms, Formidable Forms, WPForms, Contact Form 7 and Forminator. It checks the form field content and block submitting base on your keywords. Blocking IP, Country is only supported in the Pro version.</p>


BSK Forms Blacklist

Perfect

Checks field content and block submitting base on your keywords. Blocking IP, Country is only supported in the Pro version.

JP User Registration Blacklist vs BSK Forms Blacklist