Nokia Citrix UK National Cyber Security Centre PQShield This document provides guidance on integrating Post-Quantum Cryptography (PQC) into resource-constrained devices, such as IoT nodes and dedicated key-storage hardware. These systems often operate with strict limitations on processing power, RAM, and flash memory, and may even be battery-powered. The document emphasizes the role of hardware security as the basis for secure operations, supporting features such as seed-based key generation to minimize persistent storage, efficient handling of ephemeral keys, and the offloading of cryptographic tasks in low-resource environments. It also explores the implications of PQC on firmware update mechanisms in such constrained systems.