The Office of Personnel Management is not required to tell employees whether attackers who recently breached a human resources database saw their names.
The hackers, believed to be from China, apparently wanted files on staff who have applied for top-secret security clearances, The New York Times previously reported.
OPM and the Department of Homeland Security -- the agency that oversees government cybersecurity -- say there is no evidence yet the intruders compromised any “personally identifiable information.”
However, names alone are not normally considered personally identifiable information, according to OPM's definition of PII.
The affected system, e-QIP, or Electronic Questionnaires for Investigations Processing, contains names and background history records entered by the applicants themselves.
"A name alone would generally not constitute PII, but when linked to his or her Social Security number, date of birth or mother's maiden name, would constitute PII," states the definition, which was provided to Nextgov by an OPM official.
The official would not say whether the intruders accessed employee names, referring to an earlier statement that said neither OPM nor DHS “have identified any loss of personally identifiable information.”
DHS referred questions for this story to OPM. An investigation into the cyber assault is ongoing.
When asked whether he was concerned Chinese hackers could have a list of names of individuals who applied for a clearance, Robert Zitz, a 32-year intelligence community veteran who holds a clearance, said he was.
"Anyone and everyone should be concerned about anyone, any state or nonstate actor, who is using illegitimate, illegal means to be able to gather information with the express intent of doing harm," said Zitz, who served as deputy director of mission support for the National Reconnaissance Office before becoming a senior vice president at Leidos, formerly SAIC.
As earlier reported, federal officials have no yardstick for assessing whether the mere chance of detecting data loss is enough to notify potential victims. In April, the Government Accountability Office criticized agencies for poor breach notification, partly because there is no detailed policy on making disclosure decisions.
OPM and DHS declined to discuss how they decided the risk of possible data loss was not great enough to warrant notification.