It’s possible for entities with vast computing resources such as the NSA and major national governments to compromise commonly used Diffie-Hellman key exchange groups. As computing costs go down, more groups will be able to do so, exposing encryption keys to attackers. Businesses that think they might be targets of groups that have the money and know-how should at least abandon 1024-bit encryption for 2048-bit, says J. Alex Halderman, an associate Professor of Computer Science and Engineering at the University of Michigan.”]