(Natural News) Various reports claim that the United States may be preparing to strike North Korea after it conducted its sixth nuclear weapons test, over the weekend – a strike that, if it happens would likely invite retaliation from Pyongyang.

But the most damaging response the North Koreans could mount won't come from its massive artillery force or its large army: It may come via computer keyboard, in the form of a cyber attack aimed at taking down large portions of the U.S. power grid. That, or an electromagnetic pulse caused by the airborne explosion of a nuclear weapon along the U.S. eastern seaboard.

As reported by the Washington Examiner, the Pentagon – worried about reports that either the North Koreans or Iran could deploy cyber tactics or nuclear bombs against America's vulnerable electric infrastructure – is relying on the Defense Advanced Research Projects Agency, or DARPA, to come up with a defensive solution. (RELATED: North Korea Stepping Up Cyber Attacks Against The South)

The secretive agency has tasked BAE Systems, a major defense contractor, with mapping a system capable of detecting a cyber attack, as well as develop an alternative communications network that could be used by the military and civilians if the electrical grid is heavily damaged, reports the website Defense Systems.

Washington Examiner notes further:

Former CIA Director James Woolsey has been warning for years that the grid is extremely vulnerable, and recently the Pentagon and some states have taken the warning seriously. Woolsey and former EMP Commission chief of staff Peter Vincent Pry have pointed a finger at North Korea, which is now threatening the U.S.

The focus of DARPA is to prevent a cyber attack altogether, but Woolsey and Pry have also said that North Korea or Iran could also attack the grid via the atmosphere: By exploding a nuclear weapon over the east coast in an attack that would cause massive panic, instant civil unrest and result in the deaths of nine out of 10 people along the Atlantic Coast.

The DARPA plan reviewed by Defense Systems contains a number of ways the Pentagon cold react to any attack.

First off, the plan includes measures aimed at sensing an imminent attack that then triggers appropriate protective measures. If those are damaged, "it would have an alternative way for communications killed in the attack to continue in a backup system – key for the military and presumably the financial system," the Washington Examiner reported. But that system isn't going to be ready until at least 2020.

DARPA, in a statement, said it is pursuing a system capable of providing "early warning of impending attacks, situation awareness, network isolation and threat characterization in response to a widespread and persistent cyber-attack on the power grid and its dependent systems."