SHIELD4CROWD focuses on enhancing the protection of public spaces in EU cities against security threats related to crowd management. Public spaces are indeed largely exposed to several threats like UAV and UGV attacks, CBRN attacks, cold weapons/ firearms attacks or urban riots, and gatherings are by themselves a potential target for terrorist or criminal attacks. This focus is shared, from the start, by several actors and specifically by security practitioners. 3 ministries of Interior from 3 EU countries, 1 Public Transport Operator and 2 security practitioners from Poland and Slovakia are thus involved as full partners. Many other end-users will also be involved through the User Observatory Group (UOG) and some of them have already expressed official interest for the project. SHIELD4CROWD implements a progressive and iterative process to jointly define one common challenge that can be tackled with identified candidate technology serving the basis for future PCP, for which the buyers group will be created during the project, through the continuous involvement of the UOG. First, 10 jointly defined Common Security Use Cases will fully describe the gaps between available solutions, existing processes and identified needs. A technological analysis of those needs will then be conducted by technological experts, including exploration of legal, societal, ethical, and environmental considerations, to allow the end users to converge to 3 uses cases, from which a SOTA analysis and 4 Open Market Consultations will be conducted. All the results will finally serve to the definition of the common challenge and the elaboration of the first set of Tender Documentation. SHIELD4CROWD includes a Security Advisory Board to manage the sensitive knowledge generated by its activities, and several advisors to guide the elaboration of a Common Challenge fully compliant with Europe’s privacy and data protection regulations.