Connected and AutomatedD riving (CAD) features rely on s e v er al key technologies to function safelyat the vehicle and compone nt level. HEADSTART (Harm onised European Solutions fo r TestingAutomated Road Transport) is a research project fund ed by the European Union tha t aims to definetesting and validation pro c e d ur e s for CAD features with a focus on three K ey Enabling Technologi es(KETs): Vehicle to eve rything (V2X) communication, Positioning and Cyber security. This paperpresent s the technical and functional requ i rements for these three KETs including w h a t is n e eded forthese technol ogies to work corre ctly (at vehicle and c omponent level) and what is needed to verify andvali d ate them in proving ground and simulation environment. The final aim is to satisfy t h e safetyrequirements to protect the veh i c l e i ts e lf and the other road users.