NSA's and U.S. Cyber Command's roles are to protect the nation from cyberattacks and foreign intelligence, Gen. Alexander said. The issue is that if you don't see a cyberattack you can't defend against it and at the moment, the NSA has no insight if Wall Street is going to be attacked, for example, he said.

Gen. Alexander pointed out that if the industry could share some limited pieces of information from their intrusion detection systems in real time, the NSA could take it from there.

The next step from information sharing is jointly developing standards that would help secure critical infrastructure and other sensitive networks, he said.

He encouraged hackers to get involved in the process. "We can sit on the sidelines and let others who don't understand this space tell us what they're going to do, or we can help by educating and informing them" of the best ways to go forward.

"That's the real reason why I came here. To solicit your support," he said. "You have the talent. You have the expertise."