Principal Crypto Engineer (TS//SCI)

K2 is building the largest and highest-power satellites ever flown, unlocking performance levels previously out of reach across every orbit. Backed by $450M from leading investors including Altimeter Capital, Redpoint Ventures, T. Rowe Price, Lightspeed Venture Partners, Alpine Space Ventures, and others – with an additional $500M in signed contracts across commercial and US government customers – we’re mass-producing the highest-power satellite platforms ever built for missions from LEO to deep space.  The rise of heavy-lift launch vehicles is shifting the industry from an era of mass constraint to one of mass abundance, and we believe this new era demands a fundamentally different class of spacecraft. Engineered to survive the harshest radiation environments and to fully capitalize on today’s and tomorrow’s massive rockets, K2 satellites deliver unmatched capability at constellation scale and across multiple orbits.  With multiple launches planned through 2026 and 2027, we're Building Bigger to develop the solar system and become a Kardashev Type II (K2) civilization. If you are a motivated individual who thrives in a fast-paced environment and you're excited about contributing to the success of a groundbreaking Series C space startup, we’d love for you to apply. The Role  As K2's Crypto Engineer, you will own the architecture and design of our Type-1 cryptographic integrations across the spacecraft and ground segment. You will carry these designs cradle-to-grave — from concept and trade studies, through implementation and integration, to NSA certification and accreditation, and into on-orbit operations. You'll define how K2's satellites protect command, telemetry, and mission data; partner with NSA, government customers, and certification authorities; and ensure our COMSEC architecture meets the bar for national-security missions while fitting the pace and scale of a high-volume satellite production line. This is a foundational role: you'll set the cryptographic standards the rest of the program builds against.  Responsibilities  Own the end-to-end architecture and design of Type-1 cryptographic integrations across the spacecraft, payload, and ground segment  Lead crypto designs from concept and trade studies through implementation, integration, certification, and on-orbit operations  Define COMSEC architecture for command, telemetry, and mission data protection, including encryption, key management, and key loading approaches  Serve as K2's primary technical interface to NSA, certification authorities, and government customers on cryptographic certification and accreditation  Drive the certification and accreditation effort, developing the artifacts, test evidence, and documentation required to achieve and maintain approval to operate  Partner with flight software, avionics, RF, ground, and security teams to integrate cryptographic functions into...