The Chinese government is behind a campaign of cyber espionage to extract America's industrial and military secrets, a Pentagon report has said, for the first time accusing Beijing publicly of being behind a hacking threat.

As China seeks to upgrade and expand its armed forces – which will include a new aircraft carrier and stealth fighter – the 92-page report raised "serious concerns" over the country's continuing efforts to steal the technologies it needs.

"In 2012 the US government continued to be targeted for intrusions, some of which appear to be attributable directly to the Chinese government and military. These intrusions were focused on exfiltrating information," the report said.

"China is using its computer network exploitation capability to support intelligence collection against the US diplomatic, economic, and defence industrial base sectors that support US national defence programmes," it added.

China reacted angrily to the accusation yesterday, repeating its long-standing denials that the hacking is government-sponsored.

A foreign ministry spokesman said that Beijing had made "representations" to the US government over the report, which it described as "not conducive to mutual trust or co-operation".

Colonel Wang Xinjun, a People's Liberation Army researcher, said the accusations were "irresponsible and harmful to the mutual trust between the sides", the official Xinhua News Agency reported.

The decision to turn up the heat on Beijing represents a change of tactics in Washington, where diplomats say that they have made behind-the-scenes diplomatic representations to China over the issue.

Attacks

The Obama administration has signalled its determination to bolster America's defences against cyber spying and attack, asking Congress for a 21pc increase in Pentagon cyber security budgets this year.

The threat was highlighted this week as a band of hackers, under the name #OpUsa, promised widespread attacks on US government websites in reprisal for American foreign policy in Iraq, Afghanistan and Pakistan.

"What concerns me is the extent to which China's military modernisation occurs in the absence of the type of openness and transparency that others are certainly asking of China," said David Helvey, deputy assistant secretary of defence for East Asia, at a Pentagon briefing on the report. (© Daily Telegraph, London)

Irish Independent