Cybersecurity and privacy (CS&P) threats increasingly impact our daily lives, our national infrastructures and our industry. Recent newsworthy attacks targeted nationally important infrastructure, government systems, researchers, and research facilities. The landscape of what needs to be protected and from what threat evolves: new technologies are released and the threat actors improve their own capabilities through experience and close collaboration. Meanwhile, defenders work often in isolation, using private data and facilities, and producing defenses that are quickly outpaced by new threats. To transform CS&P research into a highly integrated, community-wide effort, CS&P researchers need a common, rich, representative research infrastructure, which meets the needs across all members of the community, and facilitates reproducible science.<br/><br/>The SPHERE research infrastructure will offer a novel mix of experimentation capabilities, uniquely tailored to the needs of CS&P researchers and educators. SPHERE’s novel offering of diverse, rich hardware infrastructure, configurable network substrate and safe network policies will support novel CS&P research in emerging areas, such as IoT, cyber-physical systems, programmable networks, edge computing, Internet measurement and human-centric CS&P. SPHERE’s novel user portals will democratize access to CS&P research, and will facilitate practical CS&P education of broad student populations. SPHERE’s novel support for representative experimentation and reproducibility, tight collaboration with researchers and close alliances with artifact evaluation committees, will enable vertical progress in the science of CS&P. The SPHERE research infrastructure will transform CS&P research, from piecemeal and opportunistic to highly integrated, by unifying the community’s experimentation efforts on a common, rich, highly usable infrastructure. Integrated research efforts will increase the pace of innovation and improve the success and sophistication of CS&P research products. Thus, SPHERE will significantly advance scientific discovery and the Nation’s research capabilities in CS&P.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.