BOSTON (AP) — A cybersecurity adviser to President Donald Trump is pushing to phase out the use of Social Security numbers as a form of identification.

White House Cybersecurity Coordinator Rob Joyce said Wednesday that using a person's Social Security number as an identifier or access control is "just a horrific idea."

Joyce says a federal team is looking at "what the technologies are that could change or replace these identifiers," such as using public key encryption.

He says there's no specific timeline to make changes.

Social Security numbers were among the data stolen during a hack of credit bureau Equifax that involved the personal information of 145 million Americans.

Joyce was among several federal officials speaking in Boston at the Cambridge Cyber Summit, hosted by CNBC and The Aspen Institute.