Britain's online defences will be bolstered with a new force of "cyber reservists" in the face of growing concerns over the possibility of attacks which could cripple the computer systems controlling vital national infrastructure.
The move comes as government officials revealed parts of Britain's national infrastructure, such as water and power supplies, have been mapped by hackers by what was referred to as "hostile foreign states and others".
The officials, speaking to the Press Association, would not name the countries involved although reports in the United States have said Russia and China have carried out similar "reconnaissance" exercises there.
The warning came as Home Secretary Theresa May said she wanted more powers to monitor internet activity in her data communications bill,dubbed a 'snooper's charter' by critics, to help "victims of crime, police and the public."
The first annual update of the government's cyber security strategy disclosed that the MoD were now bringing in additional experts to support their work protecting against the growing threat of cyber attack.
The MoD has already established a military Joint Cyber Unit based at GCHQ - the secret electronic communications spy agency - in Cheltenham.
The strategy document said that it was now developing "new tactics, techniques and plans to deliver military capabilities to confront high-end threat".
From next spring, the Government will launch a series of public awareness drives aimed at improving online safety for consumers and small businesses.
A new "cyber confidence tracker" will regularly track "perceptions and behaviours" to ensure the message is being delivered as effectively as possible.
Details of the new cyber reserve force will be announced by ministers next year.
A survey by consultants PwC found 93% of large corporations and 76% of small businesses suffered a cyber security breach over the past year, with costs running at up to £250,000 for larger firms.
Publishing the document, Cabinet Office Minister Francis Maude said: "There exist real and growing threats to our interests in cyberspace: these threats have increased concurrently with the growth of the 'internet economy'."