**David Alexander** has over 20 years’ experience in the field of information security. He has an MSc in Information Security from Royal Holloway, University of London and specialises in advanced network security, information security architectures, cryptographic protocols and the security of operational technology/industrial control systems. He is Senior Security Architect for the Urenco Group. David has worked on the design and assurance of critical national infrastructures around the world and has wide experience of commercial, central government and defence projects. Involved in IT for over 30 years, the first 10 in mainstream IT before he changed sides from ‘poacher to gamekeeper’, David is a Fellow of [[BCS]] and of the Chartered Institute of Information Security, and a Chartered Security Architect and IT professional. He was also one of the first people in the world accredited as Lead Auditor for what is now ISO/IEC 27001, a certification he has maintained through all the versions. As well as working for Urenco, David teaches the Network Security module on the Royal Holloway Information Security MSc programme.