Why identity management has rapidly become the new security perimeter for UK Defence.

by Jo Miller, Microsoft

In an era where adversaries no longer need to break in but simply log in, identity has emerged as the new frontline of cyber defence. In this compelling article, Jo Miller of Microsoft explores how artificial intelligence is reshaping the security landscape—both as a threat and a tool for resilience. Drawing on recent threat intelligence and operational insights, Jo makes a powerful case for identity management as the cornerstone of modern enterprise security, particularly within Defence. With machine identities vastly outnumbering human users and AI-enabled attacks growing in sophistication, this piece underscores the urgency of adopting zero-trust principles and AI-driven defences to safeguard our digital perimeter.

Jo Miller

Jo Miller is the National Security Officer at Microsoft, and a career security and technology professional. She has held various senior executive roles across the public sector, primarily in national security and defence, as Director for Serious and Organised Crime, and then Chief Data Officer in the Home Office, specialising in the intersection between security, technology, and geopolitics. A Policy Fellow at the University of Cambridge, where she has explored and assessed the judgements that the UK makes on threats to its national security, and an active advocate for women in under-represented industries, especially snowsports, technology, and security.

'Cogito, ergo sum - I think, therefore I am. And if I think hard enough, I can be you. Or I can pretend to be you. I can pretend so well that I will be invited in as you, welcomed as you, entrusted as you. I can be you.

Why identity management has rapidly become the new security perimeter for UK Defence.

AI has fundamentally shifted our understanding of, and management of, identity. Who we are and who we say we are. Who and what recognises us. Helpfully, large language and small language models have been developed to ‘think’ - to predict and reason based on what the model has seen before and the data it has been trained on. That is all modelled on healthy and well-established human behaviours that have evolved over millennia.

These technologies, however, are also being leveraged to bypass MFA (multi-factor authentication) on our devices, and to exploit our credentials at scale. Adversaries are using generative AI to create deep fake imagery and videos, to impersonate and misuse our identities, to fundamentally rewire how we protect and secure our identities, in an increasingly connected and uncertain digital landscape.

Link to full article.