Cyber attacks sure to target infrastructure: NSA chief

The head of the US National Security Agency (NSA) has urged top computer security specialists to harden the nation's critical infrastructure against ''inevitable'' destructive cyber attacks.

"This is an important time," Gen Keith Alexander, who is also the head of the Pentagon's US cyber command, said during a presentation at a conference in San Francisco, on Thursday.

"Most of the destructive tools being developed haven't been used; we need to use this window of opportunity to develop defences."

The US military should have the authority to defend "critical networks" from malware and other disruptions, Alexander said, adding that the NSA's "active defences" designed to defend military networks should be extended to civilian government agencies, and then key private-sector networks as well.

"I believe we have the talent to build a cyber-secure capability that protects our civil liberties and our privacy," Alexander said.

His comments come just two days after deputy secretary of defense William Lynn gave a similar warning, saying the capability clearly exists for malicious software to cause real damage at power plants, water supplies and other vital points.

"Few weapons in the history of warfare, once created, have gone unused," Lynn said. "It is possible to imagine attacks on military networks or critical infrastructure - like our transportation system and energy sector - that cause severe economic damage, physical destruction, or even loss of life."

Last month, Russia called on NATO to track down the culprits behind a Stuxnet computer worm that targeted a Russian-built Iranian nuclear power plant, saying the incident could have triggered a new Chernobyl (See: Russian scientists raise alarm over Stuxnet damage at Iran's Bushehr N plant).