password-heartbleed-thumb-v1-620x411.jpgNEW YORK — If the Heartbleed security threat teaches us anything, it’s that passwords don’t offer total protection.

That’s why many security experts recommend a second layer of authentication – typically in the form of a numeric code sent as a text message. If you’re logging in to a website from your laptop, for example, you enter your password first. Then you type in the code you receive via text to verify that it’s really you and not a hacker.

I’ve been using what’s known as two-factor authentication or two-step verification on most of my accounts for more than a year.

The idea behind these double-layer passwords is to make it harder to use a password that’s compromised or guessed. You’re asked for a second piece of information that only you are supposed to know.

To balance security and convenience, you can typically bypass this check the next time you use the same Web browser or device. It won’t help if someone steals your laptop, but it’ll prevent others from using your password on their machines. If you’re logging in at a library or other public computer, remember to reject the option to bypass that check next time.

The second piece of authentication could be your fingerprint or retina scan, though such biometric IDs are rarely used for consumer services. Financial services typically ask for a security question, such as the name of your childhood pet, the first time you use a particular Web browser or device. That’s better than nothing, though answers can sometimes be guessed or looked up. Some banks offer verification codes by text messaging, too.

The two-step requirement is fairly simple to turn on. With Google, for instance, it’s under the Security tab in your account settings. On Facebook, look for Login Approvals under Security in the settings. With Apple IDs, visit rather than the account settings on iTunes.

After you enable it, you’ll typically have to sign in to your account again on various Web browsers and devices. After entering your username and password, a code will get set to your phone. You’ll have to enter that to finish signing in. This has occasionally meant getting off my couch to grab my phone from the charger, but that’s a small price for security.

Occasionally, you’ll run into an app that won’t accept the text code. Apple’s Mail app on iPhones, iPads and Mac computers is one. Microsoft’s Outlook software is another. If that happens, you’ll have to go to your service’s settings to generate a temporary password for that particular app.

The biggest problem, though, is losing your phone. Some services will let you provide a backup number, including a friend’s cellphone or a landline phone. With Google, the code can be sent as a voice message instead of a text. Others offer a complex recovery code, which you’ll have to jot down and keep in a safe place.

I know two-layer security is inconvenient. The first password is difficult enough to deal with. But think of the inconvenience involved should someone break into your account and shut you out. Consider the use of verification texts to be insurance.