NSA chief says Sony attack traced to North Korea after software analysis

By Mike De Souza OTTAWA (Reuters) - The U.S. National Security Agency (NSA) identified North Korea as the source of the recent cyber attack on Sony Pictures Entertainment after analysing the software used in the intrusion, NSA Director Admiral Michael Rogers said on Thursday. Speaking to a Canadian security conference, Rogers explained that the discovery was part of the agency's efforts to develop software to counter cyber attacks. "We ultimately ended up generating the signatures to r