Companies running computer networks essential to U.S. economic and national security would be required to better defend their systems from spies, hackers and terrorists under bipartisan Senate legislation unveiled today.

The bill calls for identifying vital information networks and setting security requirements for companies and government agencies, says an AP report.. “We are on the brink of what could be a calamity,” Senator Jay Rockefeller, a West Virginia Democrat, said in announcing the bill on the Senate floor. “A widespread cyber attack could potentially be as devastating to this country as the terror attacks that tore apart this country 10 years ago.”

Under the legislation, the Homeland Security Department would have the power to identify systems that may cause mass casualties or catastrophic economic damage when attacked. The agency would set regulations requiring operators of critical networks to improve security. Companies would have to show that their networks are secure or face penalties.

The Senate bill is S. 2105.