The project comprises 5 workpackages – 3 technical, 1 on impact, and 1 on project management. WP1: Counter-measures and novel optical components for commercial fibre-based QKD The aim of this work package is to characterise and validate counter-measures to side-channel and Trojan-horse attacks in order to ensure the security of fibre-based QKD systems. This activity is carried on in strict collaboration with the ETSI Industry Specification Group on QKD. WP2: Metrology for commercial components for free-space QKD The aim of this work package is to establish measurement and characterisation facilities for components of free-space QKD devices. Within the scope of this project, we define the spectral range as that where silicon-based detectors are applicable, i.e. between 400 nm and 950 nm. WP3: Metrology for next generation (entanglement-based) QKD The aim of this work package is to foster the development of a measurement infrastructure for entanglement-based (next-generation) QKD systems, such as device-independent, measurement device-independent and reference-frame independent QKD. WP4: Creating Impact The aim of this work package is to ensure that the project results are provided to QKD stakeholders and end-users in a timely and appropriate manner, and that input and feedback is also obtained from them. These are the primary beneficiaries of this project, but the wider community exploiting single-photon states will also benefit from the methods, devices, calibration facilities and measurement protocols developed by this project. WP5: Management and Co-ordination This WP addresses the management and coordination of the project. It is structured into 3 separate tasks: Project Management, Project Meetings and Project Reporting.