Radar is wireless in a particularly demanding way, so it shares many of the hardware-security concerns of other RF systems but with extra complications.
14.1 Radar jamming as denial-of-service
A jammer is, in cyber terms, a denial-of-service attack at the physical layer. The countermeasures (frequency hopping, antenna nulling, LPI waveforms) are all forms of resilience engineering. The intellectual structure is identical to defending an internet service from DDoS: detect anomalous traffic, shape responses, distribute load.
14.2 Radar spoofing as a deception attack
A DRFM jammer that injects fake echoes is exactly analogous to a network injection attack. The "packet" is a radar pulse; the "fake source" is a captured-and-modified replay. Modern radars defend with cross-correlation across PRFs, leading-edge tracking, and sometimes even cryptographic authentication of pulse modulation patterns (still a research topic in the academic literature).
14.3 GPS spoofing as a related attack
Although GPS is not radar, it is one-way ranging from satellites to receivers. The same kind of spoofing attack works: transmit fake "satellite" signals at higher power than the genuine ones, and the receiver locks on. There are documented incidents of GPS spoofing being used to misdirect drones, ships, and even commercial vehicles. The DEF CON conference has hosted demonstrations. Critically, military GPS uses encrypted P(Y) code that is resistant to spoofing; civilian C/A code is not. The same principle applies more broadly: any unauthenticated radio ranging system is spoofable.
14.4 Radar side channels in chips
Modern automotive radars use FPGAs and ASICs to do the FFTs and CFAR. Like any chip, they leak through power consumption, EM emanations, and timing. A sophisticated attacker could in principle extract algorithmic state, target lists, or even key material from a connected vehicle's radar processing chain. This has not been a major operational concern yet, but as cars become more software-controlled and radars more central to safety-critical decisions, the attack surface grows.
A particularly evil variant: a roadside attacker who can spoof radar returns visible to a victim's ACC could cause the victim to brake or accelerate inappropriately. Several research papers have demonstrated this attack against production automotive radars in a lab. Fielded countermeasures are still maturing.
14.5 Radar warning receivers (RWR)
Aircraft, ships, and even ground vehicles carry RWRs: passive receivers that detect hostile radar emissions and identify the type. An incoming missile-guidance radar in target-track mode has a recognizable signature; the RWR alerts the pilot, who deploys chaff or changes heading. RWRs listen rather than transmit, much like passive cryptanalysis tools listen for power-side-channels rather than actively probing.
14.6 Through-wall imaging and privacy
UWB pulse radars at low frequencies see through drywall and detect movement, breathing, and heartbeats. Commercial products (Walabot and similar) put such radars in consumer hands. The privacy concern is real: an adversary in the next apartment can monitor whether you are home, where you are in the room, and roughly how fast you are breathing. The technology is well ahead of policy.
14.7 Counter-drone radar
Small-target detection has become a hot field. Conventional surveillance radars often miss drones (a quarter-meter quadcopter has m²) because their slow, low-altitude profile puts them in heavy clutter. Specialized radars at X or Ku band, with high range resolution and Doppler sensitivity, can pick out drones from clutter; they are paired with directed-energy weapons, RF jammers, or net-launching countermeasures.