Current European research and innovation (R&I) and security policies aim to address challenges that threaten European societies by deploying security technologies. Security technologies are typically intended to promote public safety, security and increase societal resilience. At the same time, security technologies spur controversies and can have enormous societal, legal, ethical, economic and political impact. Such technologies often infringe human rights, reproduce and reinforce power imbalances and social injustice. Civil society is rarely or restrictively involved during research and development of security technologies, and thus societal concerns might not be well addressed in this process. Security technologies and R&I should not create societal mistrust or missed opportunities to jointly build societal resilience. TRANSCEND aims to improve practices of citizen and societal engagement in security R&I: to enable individuals, and organisations that speak on their behalf, to participate actively and creatively in iterative processes of design and deployment. TRANSCEND will develop a Toolbox of methods to enhance the involvement of civil society in security R&I. The Toolbox will be tested and evaluated in four pilots, in close collaboration with diverse ‘on the ground’ organisations by bringing together transdisciplinary actors from academia, government, industry and society (Quadruple Helix). The TRANSCEND Framework will present guidelines on how to design and structure meaningful civil society and public engagement for societal impact assessment for security research technologies and present domain-specific instructions for the use of the TRANSCEND toolbox. TRANSCEND will contribute to the uptake of effective methods for citizen and societal engagement throughout the EU, so that civil society are given a louder voice, a place at the right tables and security practitioners are motivated and equipped to enhance such participation.