The Ministry of Defence and spy agency GCHQ are working on the technology amid growing fears that Kim could spark World War 3.
Insiders said the “high-end” tools could avert disaster by making warplanes or missiles heading towards Britain malfunction.
It is hoped the deterrent will ward off threats from other “hostile states” including Russia, China and Iran.
Britain is already using some cyber-weapons to disrupt enemy computer networks.
Details of the UK’s cyber capabilities emerged in a report to the House of Commons’ intelligence and security committee.
Officials said GCHQ’s efforts had increased “very substantially” since 2014, when its National Offensive Cyber Programme began.
He added: “Their use of these methods had historically been restricted by the diplomatic and geopolitical consequences if the activity was uncovered.
“Recent Russian cyber activity appears to indicate that this may no longer be the case.
“This places an ever greater importance on ensuring the security of systems in the UK – detecting and countering high-end cyber activity must remain a top priority for the Government.”
Earlier this week, the Government separately blamed North Korea for the devastating cyber attack on the NHS earlier this year.
Computer screens at dozens of NHS trusts were frozen with a warning that they would not be unlocked unless a ransom was paid.
Foreign Office minister Lord Ahmad said it was “highly likely” that the Lazarus Group, a cyber crime gang linked to Pyongyang, was responsible.
He added: “We condemn these actions and commit ourselves to working with all responsible states to combat destructive criminal use of cyber space.
“The indiscriminate use of the WannaCry ransomware demonstrates North Korean actors using their cyber programme to circumvent sanctions.”
He branded the rogue state a “massive threat” and said Britain must “step up” to stop a global conflict breaking out.
Mr Williamson said on Tuesday: “They are currently on the pathway to have ballistic missiles that could strike London.
“This isn’t just a problem for the United States, this is a global problem.
“Britain has to step up in terms of dealing with it, there are threats emerging right around the world.”