PITTSBURGH, July 7 (UPI) -- A way to guess many of the nine digits in a person's Social Security number by using publicly available information has been found, U.S. researchers said.
Carnegie Mellon University researchers said many numbers can be guessed just by starting with a person's birth date, The Washington Post reported.
The results come as concern about identity theft is on the rise and Congress is pushing legislation that would bar businesses from requiring people to supply Social Security numbers for purchases, the Post said.
"Our work shows that Social Security numbers are compromised as authentication devices, because if they are predictable from public data, then they cannot be considered sensitive," said Alessandro Acquisti, assistant professor of information technology and public policy at the Pittsburgh university and a study co-author.
"For reasons unrelated to this report, the agency has been developing a system to randomly assign SSNs," which should make it more difficult to discover numbers in the future, Social Security Administration spokesman Mark Lassiter told the Post.
The Carnegie Mellon researchers said they wanted to uncover people's numbers by first scouring what is publicly known about how the numbers are derived. The Social Security number's first three digits are issued according to the ZIP code of the mailing address on the application form. The fourth and fifth digits change slowly over years for a given region. The last four digits are assigned sequentially.
As a result, SSNs assigned in the same state to applicants born on consecutive days likely would contain the same first four or five digits, particularly in states with smaller populations and rates of birth, the research found.