THE NATION - News from July 7, 2009

Researchers have found that it is possible to guess many -- if not all -- of the nine digits in an individual’s Social Security number using publicly available information, a finding they say compromises the security of one of the nation’s most widely used consumer identifiers.

Many numbers could be guessed simply by knowing a person’s birth data, researchers from Carnegie Mellon University said. They also used public knowledge about how the numbers are distributed.

Researchers found it was far easier to predict numbers for people born after 1988, when the Social Security Administration began trying to ensure that U.S. newborns got numbers shortly after birth.

They were able to identify all nine digits for 8.5% of people born after 1988 in fewer than 1,000 attempts. For people born recently in smaller states, researchers sometimes needed just 10 or fewer attempts to predict all nine digits.

The study was reported in today’s Proceedings of the National Academy of Sciences.