(July 7) -- Public information such as a person's date and place of birth provide clues to most, if not all, of a person's nine-digit Social Security number, according to a new study by researchers at Carnegie Mellon University in Pittsburgh.
The finding, published Monday in The Proceedings of the National Academy of Sciences, is getting lots of news coverage because so many parts of the public and private sectors use Social Security numbers as proof of identity.
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The first five digits of a Social Security number can be determined fairly easily by birth information and other data that's available to the public, a study says.
The predictability of the way the numbers are assigned "exposes them to risks of identity theft on mass scales," study authors Alessandro Acquisti and Ralph Gross wrote. Acquisti is an associate professor of information technology and public policy; Gross is a postdoctoral researcher.
The first three digits of a Social Security number, known as the area number, are determined by ZIP code. The middle two numbers, called the group number, are assigned within a region and may remain the same for years. Lists of assigned area and group numbers are available through Web sites associated with the Social Security Administration, the report said.
The last for digits, called the serial number, are assigned to people in sequence.
The report found that obtaining the Social Security numbers of deceased people through death records can help narrow down possible Social Security numbers for people born around the same time who are still alive.
Predicting the numbers for people born after 1988 is easier because that's when the government began promoting efforts to assign numbers shortly after birth, the report found. It's also easier to guess the numbers of people born in small states.
How did the Social Security Administration respond to the report? A spokesman told The Washington Post that the agency has long cautioned against using the number as an identifier, but it also maintained that there is no sure-fire way to figure out a particular person's number.
The spokesman, Mark Lassiter, also told The Post that the agency is working on a system to randomly assign Social Security numbers, making them more difficult to guess.
"This report is a wake-up call," Peter Swire, the Clinton administration's chief privacy counselor, told The New York Times. "Social Security numbers are an aging technology, and we have to do serious planning for what will come next."
