Royal Navy specialists joined forces with Japanese counterparts in Tokyo to fend off cyber attacks during a large-scale cyber battle exercise.

Forty-one teams from 17 nations tested their cyber defence skills during the British Army’s Defence Cyber Marvel 3 exercise in Estonia, but with an international network plugging in from across three continents.

The Royal Navy’s cyber operations specialists based in Portsmouth are usually on the front line across the world, protecting ships and bases from threats around the clock, but were deployed to Tokyo for this valuable exercise.

They worked closely with Ukrainian teams in 2023 while in Tallinn, but this year – for the first time – formed a joint team with the Japanese Maritime Self Defence Force’s Communication Security Group.

The 22-strong team – 12 RN and 10 JMSDF – were tasked with protecting an island in the Indo-Pacific facing aggressive cyber-attacks from a ‘hostile’ nation state.

The cyber battle – which increased in its complexity throughout – helped forge closer bonds and understanding between Japanese and British personnel as they prepare to work with each other next year as the UK deploys its Carrier Strike Group to the region.

These skills are highly valuable given the ever-evolving attacks by hackers seen across the globe on a daily basis.

The team battled attacks on national infrastructure amid an ongoing insurgency in this mock island state.

Lieutenant Commander Paul Adkins, in charge of the RN team, said: “Our participation in the exercise with the Communications Support Group based in Tokyo represents a culmination of activity that only came into being last year; but has already cemented an enduring relationship with our friends in the JMSDF.

“Together we have refined and developed joint tactics and procedures that have borne fruit now, but more importantly, will serve us well in the future, particularly as we look to provide cyber assurance to CSG deployment 2025. Here we look forward to continued engagement with the Japanese Defense Forces”.

Leading Engineering Technician Joe Barnett said: “Being relatively new to Navy Cyber, it was an amazing experience to work with a cyber team from the Japanese Navy and I have learnt a lot throughout the exercise.

“The opportunity to do this, whilst also being able to explore the city of Tokyo in my downtime makes me feel that I have one of the best jobs in the RN.”

At its heart, Cyber Marvel is a test of guile and mental agility designed to stretch the most experienced cyber specialists, allowing allies and partners to learn and sharpen skills together.

The majority of the 1,000 personnel in 46 teams involved were operating from Tallinn, Estonia, at NATO’s Cyber Range, but others were dialled in from Kenya, Singapore, Philippines, India, Indonesia and Brunei and, in the Royal Navy’s case, Japan.

Each ‘blue’ team is scored on the success of its defence against attackers’ (the hostile red teams), system availability, command briefing quality, situational and reports as well as side challenges which included Digital Forensics, Artificial Intelligence, Machine Learning and Quantum Computing.
The RN/JMSDF team performed outstandingly, missing out on top spot to finish a close sixth.

The exercise created government, hospital, power plant and military networks, with the team defending critical national infrastructure from increasingly sophisticated attacks ensuring maximum availability, removing exploited vulnerabilities, and eradicating malicious actors from the networks.

The joint team regularly briefed back up to an Australian chain of command throughout the scenario and successfully maintained 100 per cent availability of Critical National Infrastructure (CNI), repeatedly removing malicious access and artifacts throughout the country’s infrastructure.

The Royal Navy team comes from the Maritime C5ISR Support Unit (MCSU) from Portsmouth, which delivers 24/7 defensive monitoring of networks from the RN Cyber Security Operating Centre on Portsdown Hill.