Today I am goin to show you how to improve your Drupal sites security a step further by adding Passwordless function to your Drupal site. We are going to use the module "Passwordless" this module replaces the regular Drupal login form with a modification of the password-request form, to give the possibility to log in without using a password.
Every time a user needs to log in, only the e-mail address is required. The login link will be sent to the user’s e-mail address, and will expire in 24 hours if not used.
Install the above three modules and configure the Passwordless module from here admin/config/system/passwordless