Recovering Cyber-physical Systems from Adversarial Attacks: Shallow, Deep and Exploratory Approaches

Core Concepts

Cyber-physical systems (CPS) are vulnerable to adversarial attacks that can lead to catastrophic consequences. This survey examines existing recovery methods to restore CPS to desirable physical states after attacks, categorizing them as shallow (without dedicated recovery controllers) and deep (with dedicated recovery controllers) approaches.

Abstract

This survey reviews 30 papers on recovering cyber-physical systems (CPS) from adversarial attacks. It first provides an overview of CPS vulnerabilities, including attack purposes, surfaces, and targets. The survey then categorizes recovery methods into two main approaches:
Shallow Recovery:

Component Redundancy: Leveraging redundant components to exclude corrupted ones and maintain system operation.
Feedback Signal Restoration: Repairing lost or corrupted sensor signals using techniques like ARIMA modeling and deep learning.
State Estimation: Predicting the actual physical state using system dynamics, either with known white-box models or learned black-box models.
Response Selection: Selecting the optimal response from a candidate set to mitigate attack impact.
Deep Recovery:

Non-Machine Learning-based Control Synthesis: Designing recovery controllers using techniques like linear programming, LQR, and MPC to stabilize the system or reach a safe state.
Machine Learning-based Control Synthesis: Leveraging reinforcement learning and other ML methods to learn optimal recovery policies.
The survey also discusses two exploratory papers that do not propose recovery solutions but provide insights to facilitate recovery research. Finally, it identifies untouched sub-domains and suggests future research directions in this emerging field.

Stats

"The global CPS market size is expected to grow from 86 billion dollars in 2022 to 137 billion dollars by 2028 [28]."
"In 2013, the worldwide CPS market is anticipated to be worth $44 billion dollars. The market for CPS is anticipated to increase by 7.6% from 2013 to 2021 [28]."

Quotes

"Cyber-physical systems (CPSs) integrate control, computing and sensing through physical components, and have been rapidly sprouting over the past years [13]."
"Unfortunately, malicious attacks mutually evolve with the development in CPS and potentially lead to catastrophes [33, 43, 44]."
"Recovery is always required. However, we find that relative few publications have addressed CPS recovery methods, compared to numerous research on detection."

Key Insights Distilled From

Recovery from Adversarial Attacks in Cyber-physical Systems

by Pengyuan Lu,... at arxiv.org 04-09-2024

https://arxiv.org/pdf/2404.04472.pdf

Deeper Inquiries

How can recovery methods be extended to handle more complex attack scenarios, such as coordinated multi-point attacks or attacks targeting the recovery mechanisms themselves

To handle more complex attack scenarios like coordinated multi-point attacks or attacks targeting the recovery mechanisms themselves, recovery methods can be extended in several ways:

Adaptive Response Strategies: Implementing adaptive response strategies that can dynamically adjust based on the type and intensity of the attack. This could involve using reinforcement learning algorithms to learn and adapt to new attack patterns.

Diversified Recovery Mechanisms: Introducing diversified recovery mechanisms that can counter different types of attacks. For example, having redundancy in recovery controllers or utilizing a combination of shallow and deep recovery techniques.

Intrusion Detection in Recovery: Incorporating intrusion detection mechanisms within the recovery process to identify attacks on the recovery mechanisms themselves. This can involve anomaly detection algorithms to detect unusual behavior during the recovery process.

Collaborative Defense: Implementing collaborative defense mechanisms where multiple components work together to detect and respond to coordinated multi-point attacks. This can involve sharing information and coordinating responses across different parts of the system.

Resilient Design: Designing the recovery system with resilience in mind, considering potential attack scenarios during the recovery process and building in safeguards to prevent attacks on the recovery mechanisms.

What are the potential trade-offs between the performance, complexity, and robustness of different recovery approaches, and how can these be systematically evaluated and optimized

The potential trade-offs between the performance, complexity, and robustness of different recovery approaches can be systematically evaluated and optimized through the following methods:

Performance Metrics: Define clear performance metrics such as recovery time, accuracy of recovery, system stability post-recovery, and resource utilization during recovery. These metrics can be used to evaluate the effectiveness of different recovery approaches.

Complexity Analysis: Conduct a thorough analysis of the complexity of each recovery approach in terms of computational resources, implementation effort, and system overhead. Consider the trade-offs between complexity and performance.

Robustness Testing: Perform robustness testing under various attack scenarios to assess how well each recovery approach can handle different types of attacks. This can involve simulated attacks, penetration testing, and adversarial scenarios.

Optimization Algorithms: Utilize optimization algorithms to find the optimal balance between performance, complexity, and robustness. This can involve multi-objective optimization techniques to find the best compromise solution.

Real-world Simulation: Conduct real-world simulations or testbed experiments to evaluate the recovery approaches in a controlled environment before deployment. This can help identify weaknesses and strengths in each approach.

Given the increasing integration of AI/ML in CPS, how can recovery techniques leverage these technologies to become more adaptive and intelligent in responding to evolving attack patterns

To leverage AI/ML in CPS recovery techniques for more adaptive and intelligent responses to evolving attack patterns, the following strategies can be implemented:

Anomaly Detection: Utilize AI/ML algorithms for anomaly detection to identify unusual patterns in system behavior that may indicate an attack. This can help in early detection and prompt response.

Predictive Analytics: Implement predictive analytics using AI/ML models to forecast potential attack scenarios based on historical data and trends. This proactive approach can enable preemptive recovery actions.

Reinforcement Learning: Employ reinforcement learning algorithms to enable the recovery system to learn and adapt to new attack patterns in real-time. This adaptive approach can enhance the system's resilience against evolving threats.

Adaptive Control: Integrate AI/ML-based adaptive control mechanisms that can adjust the recovery strategies based on the changing environment and attack landscape. This can lead to more intelligent and dynamic responses.

Continuous Learning: Establish a framework for continuous learning where the recovery system continuously updates its knowledge and models based on new data and experiences. This iterative learning process can improve the system's ability to respond to novel attacks.