Homeland Security seeks cyber counterattack system

First, there was "Einstein," the federal government's effort to protect itself from cyber attacks by limiting the number of portals to government computer systems and searching for signs of cyber tampering.

Then Einstein 2.0, a system now being tested to detect computer intrusions as they happen. And in the future? Perhaps Einstein 3.0, which would give the government the ability to fight back.

Homeland Security Secretary Michael Chertoff on Friday said he'd like to see a government computer infrastructure that could look for early indications of computer skullduggery and stop it before it happens. The system "would literally, like an anti-aircraft weapon, shoot down an attack before it hits its target," he said. "And that's what we call Einstein 3.0."