By now, you've probably been lectured about the importance of using strong passwords by your company's IT department, technology-savvy friends and any number of tech writers. You get it, so I won't repeat the lecture. However, the passwords you think are strong might not be.

A growing number of websites offer password meters during account creation. As you type in a proposed password, the meter might move from red to yellow to green, or it might simply tell you that the combination of characters you've entered is weak, medium, or strong.

Unfortunately, those meters don't work very well, according to a study by researchers at Concordia University in Irvine, Calif.

From the report:

"In our large-scale empirical analysis, it is evident that the commonly-used meters are highly inconsistent, fail to provide coherent feedback, and sometimes provide strength measurements that are blatantly misleading."

The researchers tested meters on a large number of sites including Google, Tencent QQ, Yahoo, Twitter, eBay, Yandex, Apple, PayPal, Microsoft (three different sites), Dropbox, Skype, FedEx, and the China railway customer service center.

The fact that different meters looked at the same passwords and came to opposite conclusions seemed to underline the problem. For example, the password #football1 was rated very weak by Dropbox, while Twitter said it was excellent, according to the study. The researchers also looked at the meters used in popular password managers including LastPass, RoboForm, KeePass, and 1Password and none of them performed very well.

So what's a security-conscious user to do?

Despite the potential weaknesses of password meters built into some password managers, you should use one anyway. Not only do they securely store all of your passwords, most generate random passwords. Even if those random passwords aren't perfect from a security perspective, they're likely to be much stronger than anything you can dream up in a hurry.

Of course, password managers are no more secure than the master passwords used to protect them. If your master passwords is weak, you could be in trouble. Take some time to think up a good one, and don't make it easy for bad guys to guess by including obvious clues such as your name, birth date or your kids' names.

Another smart step is to sign up for two-step verification on sites that support it, including Google and Yahoo. Two-step verification is simple — but strong. First, you use your regular password to log in. When you set up two-factor authentication, the associated site asks you for a mobile phone number. Then when you sign in and enter your password, you get a text containing another password that's required to access the site or service

What if you don't have your smartphone handy? When you set up the security on your account, you can choose not to use two-step verification again on that particular computer. From then on, the computer only asks for your password when you sign in. So if somebody who knows your password tries to sign in on another computer, they won't succeed because they won't get the text message with the authentication code.

It's not foolproof, but requiring a password and a separate authentication code makes it more difficult for unauthorized parties to access your account. You should also, of course, protect your phone with a code, password or fingerprint.

There's no reason to panic about password security. Most online hacks occur at the server level, where security is out of the user's hands, but it's still a good idea to be careful.