Group 53 applies foundational and applied cybersecurity research to the most critical challenges in national security. We develop secure systems that are resilient to adversarial threats-now and in the future. Our work spans the entire R&D spectrum: from system architecture and threat modeling, to cryptographic protocol design, secure implementation, field prototyping, and transition. Our mission is to ensure that national security systems can be trusted and relied on, even in adversary-contested environments. We work closely with mission areas and divisions across Lincoln Laboratory, enabling breakthroughs in communications, sensing, autonomy, and space systems to retain their strategic edge in real-world deployments. Collaboration across disciplines is central to our impact. Our staff includes system security researchers, applied cryptographers, software engineers, formal methods experts, and embedded systems developers. We bring modern security approaches into complex, high-stakes environments where assurance, performance, and operational realities must coexist. We are a collegial and mission-driven team. We value excellence, innovation, inclusion, and individual growth. Our culture is known for mentoring and developing PIs and technical leaders. We strive to bring out the best in our people-and our systems-so that the Laboratory, and the nation, can count on them when it matters most.