Nintendo has updated security to your Nintendo account and now offers 2-step verification for that extra layer of protection.
All one needs to do is log into your account, select “Sign-in and security settings” on the left, then click “Edit” next to “2-Step Verification settings”.
You will then be presented with the following screen to set up the process:
This process will work in conjunction to your smartphone app. A welcome addition for those who want the extra security.