The Chertoff Group is bringing four new senior advisers on board, the firm said on Wednesday.
They are Joel Brenner, Robert Butler, Bryan Cunningham and Paul Rosenzweig.
Brenner served as head of U.S. counterintelligence, under the Director of National Intelligence.
Butler was the first deputy assistant secretary of defense for cyber policy from June 2010 to August 2011.
Cunningham is an information security and privacy lawyer who worked in senior intelligence and law enforcement positions in the government, most recently serving as deputy legal adviser to Condoleezza Rice.
Rosenzweig worked as the deputy assistant secretary for policy in the Department of Homeland Security and as acting assistant secretary for international affairs.