Google’s own data proves two-factor is the best defense against most account hacks

Every once in a while someone will ask me what is the best security advice.

The long answer is “it depends on your threat model,” which is just a fancy way of saying what’s good security advice for the vast majority isn’t necessarily what nuclear scientists and government spies require.

My short answer is, “turn on two-factor.” Yet, nobody believes me.

Ask almost any cybersecurity professional and it’ll likely rank as more important than using unique or strong passwords. Two-factor, which adds an additional step in your usual log-in process by sending a unique code to a device you own, is the greatest defense between a hacker and your online account data.

But don’t take my word for it. Google data out this week shows how valuable even the weakest, simplest form of two-factor can be against attacks.

The research, with help from New York University and the University of California, San Diego, shows that any device-based challenge — such as a text message or an on-device prompt — can in nearly every case prevent the most common kind of mass-scale attacks.

Google’s data showed having a text message sent to a person’s phone prevented 100% of automated bot attacks that use stolen lists of passwords against login pages and 96% of phishing attacks that try to steal your password.

Not all two-factor options are created equal. We’ve explained before that two-factor codes sent by text message can be intercepted by semi-skilled hackers, but it’s still better than not using two-factor at all. Its next best replacement, getting a two-factor code through an authenticator app on your phone, is far more secure.

Only a security key, designed to protect the most sensitive accounts, prevented both automated bot and phishing attacks but also highly targeted attackers, typically associated with nation states. Just one in a million users face targeted attackers, Google said.

For everyone else, adding a phone number to your account and getting even the most basic two-factor set up is better than nothing. Better yet, go all in and shoot for the app.

Your non-breached online accounts will thank you.