The UK's dependence on the internet is putting more than half of its economy at risk, says the government.
In its first national security strategy, released today, the government said a large part of the UK economy was becoming increasingly reliant on global communication systems.
"It becomes even more important to manage the risk of disruption through cyberattack, whether terrorist, criminal or state-led," the document said. "The internetis also a part of our critical national infrastructure. It is both a target and opportunity for hostile states, terrorists and criminals."
The strategy warned of the internet being used by spies, terrorists and "transnational organised criminals", adding, "Organised crime groups are becoming more organised and professional and increasingly operate a portfolio approach, switching focus to wherever risk is lowest and profit highest."
Spies increasingly combined intelligence methods with new and sophisticated technological attacks, using the internet to try to penetrate computer networks, the strategy warned.
"We cannot rule out a possible re-emergence of a major state-led threat to the UKthrough forms of threat which render distance irrelevant, for example, state-sponsored cyberattack."
The government said it was alert to new threats, including cybercrime. Its strategy was to build up strong national defences and foster bilateral defence and security relationships with its allies.
"The security and intelligence agencies will continue to protect the UK against covert activity by foreign intelligence organisations aimed at political, economic and security targets, including cyberattack," it said.
UK IT supplier trade body Intellect called on the government to put resources into implementing the report's recommendations.
"We believe this is a sound strategy which will potentially help shape a cohesive response to the security threats facing the UK," said Joel Grundy, Intellect's defence and security manager. "However, the strategy on its own is not enough. The government now has to focus on effective implementation or risk it becoming another well-meaning report that ends up sitting on a shelf."
Grundy urged the government to leverage local experience, innovation and skills in response to the challenges highlighted in the report.
"The strategy correctly identifies cyberwarfare and the need for greater transparency and information-sharing as key areas," he added. "We believe the UK needs to be prepared for these types of emerging threat, and the knowledge and expertise of its people is the key to developing effective security."