SACA Cyber-Physical Systems 4 — Questions and Answers
Question 1: In a CPS environment, what is the primary purpose of a digital twin?
- To replace physical sensors with virtual ones
- To create a real-time virtual replica of a physical system for monitoring and simulation (Correct answer)
- To store historical data from physical devices
- To provide redundant network connectivity
Correct answer: To create a real-time virtual replica of a physical system for monitoring and simulation
A digital twin is a real-time virtual model of a physical system used for monitoring, simulation, and predictive analysis.
Question 2: Which communication protocol is most commonly used for time-sensitive networking in industrial CPS applications?
- HTTP/2
- IEEE 802.1 TSN (Time-Sensitive Networking) (Correct answer)
- SMTP
- FTP
Correct answer: IEEE 802.1 TSN (Time-Sensitive Networking)
IEEE 802.1 TSN provides deterministic, low-latency communication required for time-critical industrial CPS applications.
Question 3: A manufacturing CPS detects an anomaly where sensor readings deviate significantly from the digital twin's predictions. What is the BEST immediate action?
- Ignore it until a threshold is exceeded three times
- Shut down the entire production line immediately
- Trigger an alert, log the event, and initiate a diagnostic routine (Correct answer)
- Replace all sensors on the affected machine
Correct answer: Trigger an alert, log the event, and initiate a diagnostic routine
Triggering an alert, logging the anomaly, and running diagnostics allows root-cause analysis without unnecessary downtime.
Question 4: What does 'holistic security' mean in the context of CPS design?
- Securing only the network layer
- Applying security measures across physical, cyber, and human components simultaneously (Correct answer)
- Using a single vendor for all security products
- Encrypting only data at rest
Correct answer: Applying security measures across physical, cyber, and human components simultaneously
Holistic CPS security addresses vulnerabilities across physical hardware, software/networks, and human factors together.
Question 5: Which of the following BEST describes 'cyber-physical co-design'?
- Designing physical and cyber components independently and integrating them at the end
- Concurrently designing computational and physical aspects to optimize their interaction (Correct answer)
- Using software tools to simulate physical processes only
- Outsourcing physical design while keeping cyber design in-house
Correct answer: Concurrently designing computational and physical aspects to optimize their interaction
Cyber-physical co-design involves jointly developing computational and physical elements so each informs and optimizes the other throughout the process.
Question 6: In a smart grid CPS, what is the role of a Phasor Measurement Unit (PMU)?
- To convert AC power to DC for storage
- To provide high-frequency, GPS-synchronized measurements of voltage and current phasors (Correct answer)
- To manage demand response programs
- To isolate faulted sections of the grid
Correct answer: To provide high-frequency, GPS-synchronized measurements of voltage and current phasors
PMUs deliver GPS-synchronized, high-speed electrical measurements that enable real-time wide-area monitoring of the power grid.
Question 7: What is a 'man-in-the-middle' (MitM) attack specifically dangerous for in CPS environments?
- It causes permanent hardware failure
- It allows an attacker to intercept and alter control commands between components, causing unintended physical actions (Correct answer)
- It only degrades network speed without safety consequences
- It exclusively targets data storage systems
Correct answer: It allows an attacker to intercept and alter control commands between components, causing unintended physical actions
In CPS, a MitM attack can manipulate control signals between sensors, controllers, and actuators, potentially causing dangerous physical outcomes.
SACA Cyber-Physical Systems 4
In a CPS environment, what is the primary purpose of a digital twin?