It's true that few hackers would guess the name of your favorite childhood pet. But what about the people who know you? For them, guessing the answer to your "secret security question" might not be so tough, a new study says.

At the IEEE Symposium on Security and Privacy in Oakland, Calif., this week, researchers from Microsoft Research and Carnegie Mellon University presented research that shows the popular method of asking a "security question" of end users is not nearly as secure as it may seem.

According to a report in the industry publication TechWorld, the researchers conducted tests to see how well users who knew each other might guess the answers to common security questions.

"The study looked at the questions used by Yahoo, Google, Microsoft and AOL in March 2008," the report states. "In one test, the researchers paired two people together, with the email account holder saying they would not trust the other person with their password. When presented with the account holder's secret question, the other person guessed it right 17 percent of the time."

Between two people who trust each other, one partner was able to supply the right answer for a Hotmail account 28 percent of the time, the study said. Even with questions written by a user, a complete stranger could guess the answer right 15 percent of the time within five attempts, the report says.

"Our results do not give us confidence that today's personal questions make adequate authentication secret," the study says. "Those that are hard to guess are less likely to be chosen by users in the first place, and when chosen they are less likely to be remembered."

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