2Do the Two-Step With Google
Google calls its flavor of two-factor authentication, 2-Step Verification. The system works with the Google Authenticator app, which runs on mobile devices to provide the second factor. Sign up for Google 2-Step here.
3WordPress Leverages Google Authenticator
The popular WordPress blogging site is also enabled for two-faction authentication. WordPress offers its users the choice of using either SMS or the Google Authenticator. Learn more about WordPress two-factor authentication here.
4Credit Card-Size Two-Factor Authentication From eBay and PayPal
PayPal and its parent company, eBay, provide users with a pair of two-factor authentication options. Users can use SMS or they can buy a PayPal Security Key, which is a credit card-size device that generates the second factor password. Sign up here.
5LinkedIn Provides Two-Step Verification
LinkedIn has also joined the two-factor group with its two-step verification system. LinkedIn uses SMS as its delivery method for the second factor. Learn how to turn it on and off here.
6Secure Apple iOS With Find My iPhone
Apple’s two-step verification system can be set up to use either SMS or Apple’s Find My iPhone app to send users a second password. Apple has detailed the set-up process.
7Facebook Wants Your Login Approvals
Facebook refers to its two-factor approach as Login Approvals and it also relies on the use of smartphones to deliver the second factor. Facebook provides step-by-step details on how to activate Login Approvals.
8Secure Twitter With Login Verification
Twitter first launched two-factor security support in May 2013. The Twitter login verification feature uses SMS to help confirm user identity. Twitter has a support page that details how to get up and running with login verification.