PHComm is a Joomla! extension that untilize the existing two factor authentication (2FA) on your Joomla! site but the security code is sent to the user via SMS message.
Joomla two-factor authentication is one of those Joomla project improvements which can and will improve security. This is because by enabling two-factor authentication, it is practically impossible for a hacker to use a brute-force attack to guess the details of your Joomla! username and password.