Social Security Numbers Guessable From Public Data

Social Security numbers can be predicted, making them unfit to be “authentication devices” amid increasing worry over identity theft, researchers warn the Washington Post. Knowing a person’s birthday and birthplace can point the way to the first five digits, a study finds. “If they are predictable from public data, then they cannot be considered sensitive,” argues a co-author of the Carnegie-Mellon study.

The first three digits of the number are tied to an applicant’s mailing address; the next two are specific to a region, and may stay the same for years. The last four are “assigned sequentially," the Post notes. Using publicly-available death records and birth information, researchers could predict on the first try, the first five digits of the SSNs of 44% of deceased people born after 1988 and 7% of those born from 1973 to 1988. They could guess the full SSNs of 8.5% of people born after 1988 in fewer than 1,000 tries.
(More Social Security stories.)