AMES, Iowa (AP) – Iowa State University has reported a data breach that exposed the Social Security numbers of nearly 30,000 people enrolled at the school over a 17-year period. The university said Tuesday that five information technology servers on the Ames campus were hacked. They contained the Social Security numbers of people who took certain classes at the school between 1995 and 2012. The servers also had university ID numbers for nearly 19,000 additional people.

Officials say an unknown person or persons intended to generate enough computing power to create the virtual currency bitcoin. But officials do not believe the personal information was a target. There is no evidence that any of those files were accessed.

Officials have notified law enforcement. Individuals with exposed Social Security numbers will be offered free credit monitoring.