In an era of rapid technological change, quantum computing stands poised to break the cryptographic foundations upon which our digital world is built. While many organisations see quantum threats as distant and abstract, the risk of "harvest now, decrypt later" attacks is real and growing. This practical guide bridges the gap between academic research and operational security, providing a clear path to building quantum-resilient defences. Drawing on extensive PhD research into quantum computing and more than 20 years of cybersecurity experience, Jeremy Green introduces two pioneering tools: Q-SLICE, a quantum threat modelling framework purpose-built to identify quantum-relevant threats, and QUANTA, a modular quantum control framework for implementing secure security practices. Inside, readers will find:

• A thorough, accessible introduction to quantum computing principles and their security implications.
• Detailed exploration of post-quantum cryptography, NIST standards, and migration strategies.
• Real-world scenarios including military satellite communications under quantum threat.
• Step-by-step guidance on applying Q-SLICE for threat modelling and QUANTA for security control implementation and protection from quantum based threats.
• CIA-3D a modernised version of the CIA triad.

This book is designed for security architects, risk analysts, policymakers, and technology leaders looking to future-proof their organisations against the coming quantum era. With practical recommendations, clear frameworks, and a strong research foundation, Quantum Security equips readers to understand, assess and mitigate the risks posed by quantum computing.