I recently made the rounds and changed all the passwords I use. Experts say that you should do so every three months. I was overdue.

In the old days, I used passwords based on license plates of cars I used to own. For example (and I’m making the numbers up), say I once drove an old beater with a license plate of JBS 887. That combination of letters and numbers then became my password: jbs887. But today that would be considered a weak password, which is why I “retired” all those passwords years ago.

How do you know what makes for a weak password? In a word: monotony. Or rather, it is variety that makes for a strong password. Specifically you need a mix of these things:

• Length; at least 8 characters, preferably more
• A mixture of letters and numbers
• At least one upper case letter

The password jbs887 is weak because it’s only 6 characters long and lacks an upper case letter. It’s a good password, just not for today.

To guage how well you can dream up a password, you can visit this Password Checker site:

http://www.microsoft.com/protect/yourself/password/checker.mspx

Just type in a sample password and the web page reports back to you on its strength.

Being strong, of course, isn’t enough; while RL5ct984QqyZwXp9 is a doozy of a strong password, who wants to type that in several times a day let alone remember it?

My solution is to use words and number connectors. For example, my old car was a Dakota truck and I like the number 366 for some reason. This password 366Dakota is considered Strong by the Password Checker web site (above), but the password Dakota366truck is considered Best. It’s also not that much of a pain to remember or even type.

Most people don’t take their passwords seriously, well unless their employer or some program demands a strong password. I’m continually surprised at the number of people who use passwords like password or secret or 1111 or something equally weak. Take the time and give yourself a strong, memorable password. Do it now!