Downloading: Proof of Work Captcha Plugin

For additional information on Proof of Work Captcha please read:

Note: You will need site and secret keys from to use this plugin.

Sample Captcha

Proof of Work Captcha Plugin
Captcha in the user registration form

Plugin Settings

Proof of Work Captcha Plugin

API Settings

You will need the credentials to access the required API:

  • Coinhive site key: enter the site key from
  • Coinhive secret key: enter the secret key from

Where to use

You have the option to add CAPTCHAs to the following forms:

  • user registration forms
  • anonymous item posting forms
  • anonymous commenting forms
  • anonymous messaging forms
  • use in the above forms for suspect users

Difficulty Settings

You can specify the number of hashes to used by default, for anonymous users from suspect countries (requires Geoip Plugin be enabled), and for suspect users included in the indicated suspect groups below.

Suspect Users

Select user groups that are suspected and whose members can have a different difficulty setting assigned to them when using this plugin.