Feasibility Study with Actual Space Rockets Towards Information Theoretically Secure Radio Communication

A highly secure and reliable radio communication protocol has been desired for space launch vehicles (rockets), to protect their critical flight control uplink and downlink. We have proposed a new protocol that guarantees information theoretic security, which cannot be broken even if an attacker has unlimited computing power, unlike computational security which is used in most existing cryptographic systems. The most critical part at the protocol design is to establish a reliable key synchronization between rocket and ground station, and the proposed protocol uses GNSS time information for that purpose. We have given a formal proof that the proposed protocol is robust to replay attack and H/W failures in space flight environment such as soft errors, under some timing conditions on packet propagation delay and processing latency are satisfied. In this paper, we thoroughly investigate the actual radio communication systems on our sounding rocket and satellite launcher, and confirm that the timing conditions are met during all flight phase, i.e., the robustness of their systems is guaranteed theoretically.