Healthy Family | Home Safety | Health and Wealth | Relationship Issues | Career Advice | Growing Family
Get the SixWise e-Newsletter FREE!
Google Web
Free Newsletter Subscription
Get the Web's Most trusted & Informative Health, Wealth, Safety & More Newsletter -- FREE!


Share Email to a Friend Print This

Is Your Social Security Number at Risk?
New Study Reveals How Easy it is to Guess Your SSN


How often do you give out your date of birth or your hometown? For many of us, this is information we easily divulge. Some of us even post this seemingly harmless data on social networking sites on the Web.

social security number

Be very careful sharing personal details on social network sites online. Even seemingly innocent details, like your birth date and hometown, could be used to find out your SSN.

But according to a new study by Carnegie Mellon University, it’s possible to use this very information to predict your social security number (SSN) … and from there possibly steal your identity.

How Easy is it to Guess Your SSN?

When researchers looked at grouping of SSN’s from deceased people born between 1973 and 2003, they were able to guess the first five digits about 40 percent of the time if they knew the person’s date of birth and hometown. Further, they could predict all nine digits of the SSN nearly 9 percent of the time in fewer than 1,000 attempts.

In a second study, the researchers then used birth dates and hometowns they’d found on social networking sites and tried to predict the SSN’s of 621 university students. Using the pattern they had established in the previous study, they were able to guess the first five digits of a student’s SSN on the first try for over 6 percent of the sample.

Why You Should Not Give Out the Last Four Digits of Your SSN

Many organizations, from banks to credit card companies, use the last four digits of your SSN as a way to safely identify you. However, this practice, though well-intentioned, is misguided,” according to the researchers.

Why? Because the first five digits of your SSN are the ones that are easiest to predict. The first three numbers, in fact, are based on your zip code at birth. And using a statistical pattern the researchers were able to guess the first five numbers nearly half the time, and sometimes much more.

social security number

Do not carry your social security card in your wallet or purse, as it could easily be stolen. Instead, keep it in a secured space at home or in a lockbox.

“For certain states, 90% of the time we could get the first five digits on the first attempt,” Alessandro Acquisti, a professor of information technology and public policy at Carnegie Mellon University, told The Wall Street Journal. “Although the accuracy changes from state to state and year-to-year, for some states and some years, it’s very concerning.”

Because the first five digits are easily guessed (especially by a driven cyber criminal), if they’re then able to get a hold of the last four digits used as identifiers, they can easily piece together your entire SSN.

How to Protect Your SSN, and Why You Should

Once someone has your social security number, they can easily open up bank accounts, assume credit cards and even obtain government documents like a driver's license -- all in your name.

Some of the protection, indeed, should come from the government. Acquisti recommends that the Social Security Administration begin using a truly randomized system for issuing SSN’s, and suggests financial institutions use a 2-digit identification number or a digital certificate to confirm customers’ identities.

However, you, too, have a role to play when it comes to protecting your valuable information. To help keep your SSN from falling into the wrong hands:

  • Be careful with what details you reveal on social networking sites

  • After first applying for your child's social security card, make sure it arrives in the mail

  • Do not carry your social security card in your wallet, where it could be stolen.

  • Only give out your social security number when absolutely necessary. Many forms may ask for it, but that doesn't mean you have to give it out. Be especially careful when giving out your SSN online or through email.

  • Check your credit report at least once a year to monitor for fraudulent activity. All three credit-reporting agencies now give you one free copy per year.

If you believe someone has fraudulently used your social security number, you should contact the Federal Trade Commission for help.

Recommended Reading

How to Create the Best Passwords: Prevent Password Theft and Loss with These 11 Password Creation & Organization Tips

The World's #1 Internet Threat May Be Robbing Your Identity Right Now 


Proceedings of the National Academy of Sciences July 7, 2009;106(27):10975-80.

The Wall Street Journal July 9, 2009

To get more information about this and other highly important topics, sign up for your free subscription to our weekly "Be Safe, Live Long & Prosper" e-newsletter.

With every issue of the free newsletter, you’ll get access to the insights, products, services, and more that can truly improve your well-being, peace of mind, and therefore your life!

Share Email to a Friend Print This