2Factor Cheaper Alternative to DuoSecurity?

[sushlik]

Hello,

WHMCS supports Two-Factor-Authorization (TFA) via DuoSecurity, but it seems quite expensive to use their service with monthly costs starting at 3,- USD per user! I have a hosting-plan starting at 2,80 and would like to offer TFA via SMS.

Does anybody know a good alternative to DuoSecurity that can be used with WHMCS easily?

Thank you and kind regards,
Sascha

[sentq]

if your ideas is to provide this feature for your clients then I would recommend Google Authenticator.