Is UK doing enough to protect itself from cyber attack?
In 2010 the British government designated the protection of computer networks as one of the country's most important national security priorities. In its Strategic Defence and Security Review (SDSR) it pledged, "the National Cyber Security Programme will be supported by £650m of new investment over the next four years".
What exactly has this investment bought, three years on?
Speaking on and off the record to insiders - from the government, intelligence agencies and security industry - it is apparent that the achievements in defending the UK from this threat have disappointed many.
Much of the available funding may actually have been directed at improving the UK's ability to target other countries' computer secrets.
Some point out that even if everything had gone to plan, an investment averaging £162.5m per year over four years could only have a limited effect on such a huge problem.
Security experts estimate that there are about 50 million cyber attacks a year in the UK, a number which they say is growing rapidly all of the time, and they put the damage to the UK economy at up to £27bn last year.
Yet, even according to government plans, less than half the total money committed has so far been spent.
There are suggestions that early strategising consumed many precious months and that the Cabinet Office, which is supposed to be giving overall direction to the project, has not yet allocated much of the money to specific projects.
"Some people have… said we're saving money for a rainy day," Mark Phillips, who helped draught the government's strategy, and is now at the Royal United Service Institute (RUSI) think tank, says. "To which my response is that we already have a rainy day, we have a high threat already with cyber."
Francis Maude, the minister responsible for cyber security, disputed this interpretation in a statement to BBC Newsnight, saying:
"Far from abdicating our responsibility on funding, to date we have spent over one third in the first two years of the programme. We are on target and in line with our public spending forecasts. The rapidly changing nature of cyber threats to the UK demonstrates the need for a flexible cyber security response so we reassess our spending priorities on a regular basis as was always the case. This is a prudent, sensible, smart approach as we move forward into the final two years of the programme."
Even if the full £650m is spent, as those close to the policy insist it will be, it is apparent that this will be done over five years rather than the originally promised four.
The other striking thing about the capability that has been taking shape is its offensive character; official figures show that 59% of the planned spend is meant to go to the intelligence agencies.
"We can achieve a tremendous amount these days through remote exploitation rather than face to face meetings with agents," says an MI6 officer referring to attacks on computer networks.
"GCHQ's offensive capability gives the UK an edge," a former senior officer at the eavesdropping centre in Cheltenham told me, adding, "a large proportion of that money has [therefore] gone into those capabilities".
John Bassett, now at RUSI and formerly GCHQ's Senior UK Liaison Officer in Washington, adds that much of the new government funding has gone on, "existing programmes... designed to get a really strong grip on global situational awareness".
Is this just a polite way of referring to stealing others' secrets?
Mr Bassett suggests that understanding the threat to UK computer security requires the exploration of adversary capabilities.
This argument, that the UK's defence requires the penetration of other countries' computer networks makes it hard to define whether most of the British cyber-security spend is actually going on offensive work - hacking for want of a better term - or whether that activity only accounts for some of it.
However, everybody one speaks to within the circle of secrecy assumes that this type of activity has consumed a significant proportion, measurable in the tens of millions, of the UK's total spending on cyber elements.
That emphasis on offensive work is remarkable given that the SDSR and the government cyber security strategy published in 2011 explained the rationale for the new spending almost entirely in terms of protecting the UK economy and government from attack.
Indeed, at an SDSR press briefing in 2010 a senior government official who I asked whether the UK even had an offensive cyber programme declined to confirm that it did, although another official subsequently contacted me to say that there was such an effort.
Mark Phillips, who was present at many of the meetings that formulated both policies, told us that the offensive programme was "one of the two unstated objectives" of the cyber security plan. The other, he implied, was providing support to allies, which in an intelligence context is usually taken as a reference to the US.
The UK Ministry of Defence (MoD) meanwhile has taken 14% of the new money for cyber security, spreading it more or less evenly between offensive and defensive roles, insiders suggest.
It has launched Project Watchtower - a series of programmes designed to crated a super secure cyber architecture for the MoD -in an attempt to secure the military's computer networks from sophisticated attacks, with experts suggesting some good progress has been made.
On the offensive side, the MoD has established its Joint Cyber Unit, based at Cheltenham. The impetus for the creation of this outfit, several dozen strong, came from Nato's bombing campaign in Libya, says one Whitehall player.
Ministers asked why the MoD did not have the capability to switch off the Libyan air defence system from afar by means of cyber attack.
One MoD insider argues that the UK is some way from being able to take action of this kind, or match the unleashing of the Stuxnet virus on Iran's uranium enrichment plant, widely believed to have been carried out by the US, although they have not officially admitted it, but that the hold-up is on the policy and legal front rather than the issue of technical ability.
There has been a lively discussion among Whitehall law officers about whether the use of such a cyber attack would constitute an act of war or could under certain circumstances, for example switching off power to a hospital, be construed as a war crime.
Increasingly it is in this area, the development of cyber weapons or disruptive malware, rather than in the long established game of stealing secrets - state or commercial - that attention is focussing in the security community.
In 2011-12, for example, the US Department of Homeland Security tracked 23 cyber attacks on companies related to the national gas pipeline system. They assessed that the targeted information would have allowed an intruder to blow up hundreds of compressor stations, blacking out the US energy grid, "at the click of a mouse". Oil installations in Iran and Saudi Arabia have also had their control equipment hit by malware.
Mr Maude stressed to us that the UK's programme is "not just about securing government systems, though it helps do that too, but underpins all our objectives in tackling cyber crime, protecting our critical national infrastructure and making the UK one of the safest places in the world to do business in cyberspace." He noted that the Economist Intelligence Unit has put Britain top among the G20 countries for creating a secure environment for networks.
Notwithstanding this accolade, there is widespread concern about the vulnerability of the UK's national infrastructure to attacks of this kind.
"I don't think anyone is any more secure than they were," said Rashmi Knowles, Chief Security Architect at RSA, a leading cyber security firm, when I asked her whether Britain's infrastructure is any better protected than when the government launched its initiative in 2010.
In part this stems from constant evolution of the threat, with hackers far more dynamic, constantly evolving new techniques, than the government bureaucracies that try to stop them. As for the work that has been done to thwart them, some sectors, such as banking, have a far greater interest in investing in secure networks than the likes of public utilities.
Nightmare scenarios such as hijackers taking control of an aircraft via its computerised systems, or shutting down a national power system or a country's entire internet, appear feasible in the light of the US gas pipeline case. To what extent such risks are exaggerated by security firms touting for business is open to argument.
What almost all parties in the cyber security sector agree is that awareness of the risks is growing. For the government experts trying to devise a response, the risk is that their solutions may be judged inadequate to the scale of that challenge.