I’m hearing from more users about protecting their online identities, and I got a question this week about two-factor authentication, which the reader had heard of but didn’t quite understand.

Two-factor authentication is a way to provide more protection when you access your online accounts.

I have two-factor authentication enabled for my Apple ID, online banking, Amazon account, Twitter, Facebook and Google accounts.

HOW IT WORKS

Most companies’ implementations of two-factor authentication involve associating a trusted device — usually a cellphone — that you’ll use during the login process. Some also use a phone call.

Instead of logging in with just a username and a password, you’ll be texted or called with a code that you enter into a secondary login screen to gain access.

This way, for someone to gain access to your account, they would have to know your password and have your phone.

Usually you’ll only have to do two-factor authentication the first time you log into your account on a new device or with a new browser.

The system should offer to remember the login so it won’t need to send you a code again for that device. If you want to make things as secure as you can, you can set it up so you have to enter the two-factor authentication code every time you log in.

HOW TO SET THINGS UP

Make a list of the accounts you’d like to secure. Then call up your accounts, head to the security preferences and look for two-factor authentication.

Twitter calls it login verification. Facebook has a section on the security and login settings to enable two-factor authentication.

Apple lets you turn it on from your phone or a browser. From your iPhone, go to Settings, then iCloud, then Password and Security.

From a browser, go to icloud.com and then Settings, then scroll down to the Security section.

Android users will find the experience the same. Look for two-factor authentication wherever you find your user profile. Securing your Google accounts and any other app store accounts will help.

Is it rock-solid safe?

No. Two-factor authentication is not 100 percent safe. Nothing is, but using two-factor authentication is much more secure than using only a password.

———

Jim Rossman writes for The Dallas Morning News. He may be reached at jrossman@dallasnews.com.