Switching activity in chips, buses, and clocks radiates EM energy that can be captured and analyzed to reveal internal computation. Near-field probes (in test) or proximity receivers (on-orbit assets) can observe harmonics and modulation tied to cipher rounds, key schedules, or protocol framing, sometimes with finer granularity than power analysis. Coupling paths include packages, harnesses, SDR front ends, and poorly shielded enclosures. By training on known operations and comparing spectra or time-domain signatures, an adversary can recover keys or reconstruct processed data without touching logical interfaces.
| ID | Name | Tiering | Description | NIST Rev5 | ISO 27001 | Onboard SV | Ground | |
| CM0003 | TEMPEST | The spacecraft should protect system components, associated data communications, and communication buses in accordance with TEMPEST controls to prevent side channel / proximity attacks. Encompass the spacecraft critical components with a casing/shielding so as to prevent access to the individual critical components. | PE-19 PE-19(1) PE-21 SC-8(3) | A.7.5 A.7.8 A.8.12 | ||||
| CM0050 | On-board Message Encryption | In addition to authentication on-board the spacecraft bus, encryption is also recommended to protect the confidentiality of the data traversing the bus. | AC-4 AC-4(23) AC-4(24) AC-4(26) AC-4(31) AC-4(32) PL-8 PL-8(1) SA-3 SA-8 SA-8(18) SA-8(19) SA-8(9) SA-9(6) SC-13 SC-16 SC-16(1) SC-16(2) SC-16(3) SC-8(1) SC-8(3) SI-19(4) SI-4(10) SI-4(25) | A.5.14 A.8.22 A.8.23 A.8.11 A.5.8 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 A.5.33 A.8.24 A.8.26 A.5.31 A.8.11 | ||||
| CM0060 | Secret Shares | Use of secret shares in which the original computation is divided probabilistically such that the power subset of shares is statistically independent. One of the major drawbacks of this solution is the increase in the power consumption due to the number of operations that are almost doubled. | PE-19 PE-19(1) | A.7.5 A.7.8 A.8.12 | ||||
| CM0061 | Power Masking | Masking is a scheme in which the intermediate variable is not dependent on an easily accessible subset of secret key. This results in making it impossible to deduce the secret key with partial information gathered through electromagnetic leakage. | PE-19 PE-19(1) | A.7.5 A.7.8 A.8.12 | ||||