312-50 Question 408
Single answer▪ IoT ConceptsDuring an authorized assessment of a smart building, you discover several battery-powered temperature sensors communicating with a central gateway over a low-power wireless network. The sensors transmit small telemetry messages infrequently, have very limited CPU and memory, and are expected to operate for years without battery replacement. The client asks which wireless technology is most likely being used so the team can plan protocol-specific testing. Which technology best fits this IoT deployment scenario?
- A
LoRaWAN
- B
Bluetooth Classic
- C
NFC
- D
EtherCAT
Show answer and explanation
Correct answer: A
Explanation
The scenario points to a Low-Power Wide-Area Network (LPWAN) use case: small messages, infrequent transmission, constrained devices, and multi-year battery life. Among the options, LoRaWAN is the best match. In real CEH engagements, correctly identifying the IoT communication model is important because attack surfaces differ significantly by protocol. For LoRaWAN, an assessor would examine device provisioning, activation mode (such as OTAA vs. ABP), key handling, gateway exposure, backend APIs, and whether telemetry is protected end to end. By contrast, NFC is proximity-based, Bluetooth Classic is short-range and not optimized for this power profile, and EtherCAT is wired industrial control networking. This aligns with common IoT architecture guidance from the LoRa Alliance and general IoT best practices from NIST, which emphasize understanding constrained devices, communication range, power constraints, and protocol-specific security controls before testing.
- A. Correct.
Correct. LoRaWAN is designed for low-power, long-range IoT communications with small, infrequent payloads and long battery life. It is commonly used for sensors such as environmental monitors in smart buildings, smart cities, and industrial telemetry. From a CEH perspective, identifying LoRaWAN helps guide testing toward gateway exposure, device activation methods, key management, and backend application security.
- B. Incorrect.
Incorrect. Bluetooth Classic is generally used for shorter-range, higher-throughput use cases such as audio peripherals and continuous device connections. While Bluetooth-based IoT exists, Bluetooth Classic is not the best fit for long battery life and sparse telemetry across a building or campus compared with LPWAN technologies.
- C. Incorrect.
Incorrect. NFC is an extremely short-range technology typically used for tap-to-pair, payments, access cards, and very close proximity exchanges. It is not suitable for periodic sensor telemetry to a central gateway over building-scale distances.
- D. Incorrect.
Incorrect. EtherCAT is an industrial Ethernet fieldbus technology used for real-time automation on wired networks. It is not a low-power wireless technology for battery-operated sensors, so it does not match the described deployment.