Cyber attacks pose the biggest threats to national security, says former Department of Homeland Security Secretary Michael Chertoff.

Cyber attacks against companies like Lockheed Martin, Northrop-Grumman, Sony, Google, Visa and Mastercard, among others, show just how vulnerable the economy is to tech-savvy terrorists.

"This is the biggest threat we currently face," Chertoff tells Yahoo's The Daily Ticker.

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"Not only is there a concern about our critical infrastructure … but we are losing billions of dollars of intellectual property every year that is being stolen and it is resulting in job losses and damages to our economy."

A Federal Emergency Management Agency report estimates cyber attacks jumped 650 percent from 2006 to 2010, Yahoo adds, pointing out 60 percent of U.S. companies have reported security breaches.

Half of the country's so-called "high-priority facilities" like those that manage the country's electrical grids reported having been attacked.

Many attackers aren't necessarily enemies of the U.S. but rather, are looking for a leg up to compete, Chertoff adds.

"For many nations, they view the economic well-being of the country as part of their national security strategies. They will use their intelligence agencies as a way to enable their companies, their national champions, to compete in the market place," Chertoff says.

"We don't do that in the United States. We keep the free-market separate from government, but as a result sometimes we have our rivals overseas stealing our assets."

U.S. and Chinese defense ministers have agreed to cooperate on cyber issues to avoid future crises, with China saying it takes too much blame for cyber attacks on U.S. interests, adding other countries are to blame.

"Obviously there are other countries, actors, others involved in some of the attacks that both of our countries receive," Defense Secretary Leon Panetta told reporters after a meeting in the Pentagon with Chinese Defense Minister General Liang Guanglie, the Associated Press reports.

"But because the United States and China have developed technological capabilities in this arena it's extremely important that we work together to develop ways to avoid any miscalculation or misperception that could lead to crisis in this area."

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