Side-Channel Attack - EX-0015

Adversaries extract secrets or steer execution by observing or perturbing physical byproducts of computation rather than the intended interfaces. Passive channels include timing, power draw, electromagnetic emissions, acoustic/optical leakage, and thermal patterns correlated with operations such as key use, counter updates, or parser activity. Active channels deliberately induce faults during runtime, e.g., voltage or clock glitches, electromagnetic/laser injection, or targeted radiation, to flip bits, skip checks, or bias intermediate values. On spacecraft, prime targets include crypto modules, SDR/FPGA pipelines, bootloaders, and bus controllers whose switching behavior or error handling reveals protocol state or key material. With sufficient samples, or with repeated fault attempts, statistical features emerge that reduce entropy of the sensitive variable under study; in effect, a successful fault campaign turns into information leakage comparable to a passive side channel. Collection vantage points range from on-orbit proximity (for EM/optical), to ATLO and ground test (for direct probing), to instrumented compromised hardware already in the signal path.