- Bargaineering - http://www.bargaineering.com/articles -

Could Someone Guess Your Social Security Number?

Not too long ago, researchers at Carnegie Mellon University conducted a study related to identity. They attempted to guess Social Security numbers [3] using publicly available information. What they found was that it is possible to guess, correctly, the first five digits in 44% of the deceased born after 1988.

When the researchers turned to the living, they found that they could predict the Social Security numbers [4] for 8.5% of people born after 1988 in fewer than 1,000 attempts. And, for some people, it was possible to predict an entire Social Security number in less than 10 tries. While 8.5% doesn’t seem like a large portion of the U.S. population, you should realize that it nevertheless represents more than 25 million people. That’s a lot of Social Security numbers at risk — just by guessing.

How the Government Assigns Social Security Numbers

For decades, there has been a method to assigning Social Security numbers. The first three numbers are assigned based on where you live. So, the ZIP code on the application is taken into account. Then, the next two are a “group number” that is also assigned based on region. These numbers change over the years, as more people are born. However, if you live in a region that isn’t very populous, the number could remain the same for years. Finally, the last four numbers of your Social Security number are assigned sequentially. (It is significant — and scary — to realize that the last four digits are likely to be the most unique part of your number, and these are the very numbers not “blacked out” on forms.)

Guessing Your Social Security Number

One of the first places to go for Social Security number guessing is the publicly available “Death Master File.” It lists names, birth dates, and states, along with full Social Security numbers. This can provide clues about what someone else’s first four or five numbers might be, based on where they were born. Those born in smaller towns are at a disadvantage, since it can then be a little easier to guess the last four digits, based on sequence. (Hence the 1,000 tries it took to accurately guess all nine digits in 8.5% of the cases.) With a computer program designed to try possibilities, this shouldn’t take too terribly long.

Of course, the next issue is the fact that information about you is publicly available. While some might go through public records, many people have only to look at a Facebook account, or some other social media. Even if you don’t share your birth year along with the date, the fact that you’ve indicated you are a member of the high school class of 2001 can be a helpful hint to when you were born. And many people list their birth towns as their home towns. So, armed with that information, it might be possible to guess Social Security numbers.

What’s the Government Doing?

Originally, these numbers were strictly supposed to be used for tax purposes and Social Security benefits. They weren’t supposed to be an identification number. And how’s that working out? We all know that the Social Security number has become a de facto national ID.

But, for the last couple of years, the government has been working on randomly assigning numbers, rather than working off a system. While that might be good for your kids, it still means that your Social Security number might be guessable. But, it still takes some work to get to that point, and chances are that an ID thief [5] is more likely to get your number by hacking a database than by guessing it.

(Photo: TheLawleys [6])