We can make any application more secure (and safer from bots or hack attempts) by providing two-factor authentication. Two-factor authentication requires an individual to verify their identity using two separate methods. One such method, SMS text verification, has become quite popular, due to its convenience and difficulty in mimicking. This recipe will show you how to create two-factor authentication in a Meteor app, using the Twitter OAuth and Twilio SMS services.
Using the Customizing the accounts login recipe found in this chapter, we already have an application that authenticates against Twitter. We will expand that recipe, and add the Twilio SMS service to send a 6-digit verification code for our second authentication challenge. So that we can focus on the authentication part of the recipe, we will set up the Twilio service here rather than in the main recipe.