The purpose of this document is to provide air navigation service providers with an introduction to cyber security in air traf c management, including the cyber threats and risks and motives of threat actors, as well as some considerations to managing cyber risks and implementing a cyber security programme. The appendices include information on standards and a framework for cyber security, and some practical guidance to conducting a cyber risk assessment – a recommended rst step to understanding and managing the cyber security risks to systems, assets, data and capabilities in ATM.