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.