A widely used method of computer encryption has a little-noticed problem that could allow confidential data stored by almost all Fortune 500 companies and everything stored on U.S. government classified computers to be “fairly easily” stolen or destroyed.
The warning comes from the inventor of the encryption method, known as Secure Shell or SSH.
As a teenager in the 1990s, Sean M. Bodmer hacked government computers and was arrested by the FBI. Today, he is a top researcher at the computer security firm CounterTack, based in Waltham, Mass.
Mr. Bodmer described how a hacker could use abandoned keys to move through a supposedly secure computer network by hopping from server to server.
“It’s a domino effect” security breach, he said.