Cities around the world are facing urgent privacy and cyber-physical security threats that will change how they are working with Smart and sustainable solutions. Meanwhile, cities in the EU are confronted with new regulations that will force the processes and systems that control data at a city level to be changed and redesigned. In this report, Smart City Catalyst addresses the lacking knowledge of how cities are currently approaching these realities and provides basic guidelines and recommendations for city actors interested in improving cyber-physical security and upholding the privacy of citizens.