Design and in-orbit Demonstration of a Post-Quantum Cryptographic Solution Based on KEMTLS-PDK to Enhance Satellite Communication Security

In recent years, cyber-attacks leveraging quantum algorithms like Shor’s and Grover’s, executed on cryptanalytically-relevant quantum computers, have demonstrated their potential to compromise and break the cryptographic systems currently safeguarding information systems. Recognizing the urgent necessity to bolster data and communication security in the quantum age, the National Institute of Standards and Technology took a significant step in July 2022 by announcing the four post-quantum cryptographic (PQC) algorithms to standardize by 2024. Notably, Kyber was chosen as key establishment algorithm, marking a pivotal transition towards quantum-safe cryptographic solutions. In the realm of space technology, current space systems predominantly rely on symmetric cryptographic primitives. However, there is a growing imperative to incorporate asymmetric cryptography into future systems. This strategic shift is driven by the overarching objectives, including enhancing flexibility for federated operations, adopting digital signature-based authentication, improving scalability – essential in new space and for projects with large constellations – and fostering interoperability with terrestrial systems. Security disruption in space systems, particularly in terms of data integrity and authentication, can have profound consequences during data transmission to and from spacecraft. Data may be corrupted, manipulated, or sent by malicious actors, and unauthorized operations may be performed, representing significant risks. In extreme cases, these risks could result in mission failure, loss of human lives in the case of crewed missions and causing harm to people and property. Furthermore, the lack of data confidentiality in communications between satellites and between ground stations and satellites could expose private and sensitive information to untrusted parties. Therefore, given the quantum threat mentioned earlier, it is necessary to begin adopting quantum-resistant asymmetric cryptographic primitives in space systems. The current Master’s Thesis project was conducted during the internship at the European Space Operations Centre of the European Space Agency (ESA). The Thesis objective is to design and implement a specific solution that integrates Post-Quantum Cryptography into space missions to secure sessions between ground-based Mission Operations (MO) applications and those on spacecraft. To achieve this, a new MO service called Security Service is introduced. It implements KEMTLS-PDK protocol with Kyber512 as key establishment algorithm, and it is used to exchange encrypted messages after the successful creation of a secure session. Software security modules are used for key material storage and a Public Key Infrastructure on ground is employed for generating, revoking, and verifying the X.509 public key certificates of the nodes. The entire implementation has been built on top of the CCSDS (Consultative Committee for Space Data Systems) MO Message Abstraction Layer (MAL), operationally used by ESA OPS-SAT spacecraft, to ensure ability to demonstrate the project in orbit. The implementation was tested in a real-life scenario, firstly with OPS-SAT satellite’s Engineering Model to provide a representative example of execution, and subsequently during a live ground-station pass with the flying satellite.