Make registration only possible after confirming the privacy policy with a checkbox?


is there an easy way to implement an checkbox that users have to actively set in order to allow registration?
I want to use the Welcome Message in Global Administration > Registration and inform over out xwikis privacy policy.

However some law interpretations are, that it is necessary that users explicitly have to actively confirm that they read and agree to the privacy policy before private data can be processed. Because of that many websites have an check box that you have to click before registration can be successful.

When the data privacy acceptance checkbox is not confirmed it should be blocked to click the registration button.
Can it be done with velocity macro inside the welcome message or would it be required to modify the /xwiki/bin/view/XWiki/Registration page?