Google Apps 2-step verification
Why you should use 2-step verification
2-step verification adds an extra layer of security to your Google Account by requiring you to have access to your phone – as well as your username and password – when you sign in. This means that if someone steals or guesses your password, the potential hijacker still can’t sign in to your account because they don’t have your phone.
A mobile phone that can receive the verification code via text message or phone call. These devices use the free Google Authenticator mobile app to generate the verification code.
Set up directions are found here: