The difference between secure computing and falling victim to online fraud or identity theft often comes down to a dozen or so keystrokes: your password and your answers to those security questions that websites figure only a real user would know.

In the first of two parts, Scam Alert provides tips on how to choose hard-to-crack passwords that are easy to remember. Next week, we explore the problems with commonly used security questions, and how to create answers to bolster online security.

You’ve heard it before: To protect your online banking, shopping and other accounts, use strong passwords—often described as having at least eight characters and a mixture of upper- and lower-case letters, symbols and numbers. Yet despite that common advice, hackers manage to break into computer accounts every 39 seconds, according to one study, and losses last year from online fraud totaled $265 million, up 33 percent from 2007, according to the FBI.

One reason: Many people continue to make poor password choices, repeating their username (johnsmith) or adding numbers to it (johnsmith123). Other commonly hacked passwords include “123456” or some other numerical sequence, the words “password” or “test,” or others on this list of worst passwords.

But even tweaking a word with symbols or numbers—say, changing “mysecurity” to “my$eCurIty”—may no longer be enough. Nor is repeating a word (mysecuritymysecurity) or even spelling it backward (ytirucesym).

That’s because sophisticated hackers often use “brute force” programs that scan for words found in the dictionary, and even combinations of them. Once a hacker cracks a password, he can change it, locking out the real user.

This may explain those cryptic passwords, such as HD4kr#wp8T49c, that are often assigned when you open a new online account. But while such passwords offer increased security, they can be hard to remember (one reason why they are usually changed to regular and hackable words).

So how can you devise hard-to-crack passwords that are easy to remember?

• Create a password by using the first letter of a favorite phrase or song lyric. For instance, “When I’m feeling blue, All I have to do, Is take a look at you,” becomes “wIfbaIh2ditAlaU.” In this way, the song “A Groovy Kind of Love” becomes a stronger kind of password.
• Combine parts of unusual and unrelated English words, such as “gastrocumulus” or “cyberplasticity,” or combine English words with those from a foreign language, such as “chienrattlesnake.”
• Use fragments of words mixed in unusual ways: “Carol loves pizza” can become “zaCarolSevolPiz” (with loves spelled backward), or weave two words together, so “Summer Flings” becomes “SFulmimnegrs.”
• It’s unwise to use birthdays or anniversaries as a password, because those dates may be available in online public records. But with a little tweaking, your hackable June 10 wedding date can be stronger when combined with the initials of your maid of honor (Susan Jones) and honeymoon designation (Miami): “SJ0610mia.”

Ideally, you should use different strategies to create different passwords on various accounts, and change them every month or so. Check the strength of each password at Microsoft’s password checker.

Sid Kirchheimer is the author of Scam-Proof Your Life (AARP Books/Sterling).