Optimal Control of Intrusion-Tolerant Networked Systems through Two-Level Feedback

المفاهيم الأساسية

The core message of this article is to formulate intrusion tolerance for a networked system as a two-level optimal control problem. On the local level, node controllers perform intrusion recovery, and on the global level, a system controller manages the replication factor. The authors design TOLERANCE, a novel control architecture that leverages this formulation to improve service availability and reduce operational cost compared to state-of-the-art intrusion-tolerant systems.

الملخص

The article presents TOLERANCE, a two-level control architecture for intrusion-tolerant networked systems.
On the local level, each node runs a controller that monitors the service replica through alerts from an Intrusion Detection System (IDS). Based on these alerts, the controller estimates the replica's state (compromised or not) and decides when to perform recovery. The local control problem is formulated as an instance of the machine replacement problem from operations research.
On the global level, a system controller collects state estimates from the nodes and adjusts the replication factor. The global control problem is formulated as an instance of the inventory replenishment problem.
The authors prove that the optimal control strategies on both levels have threshold structure and design efficient algorithms for computing them. They implement and evaluate TOLERANCE in an emulation environment, running 10 types of network intrusions. The results show that TOLERANCE can improve service availability and reduce operational cost compared to state-of-the-art intrusion-tolerant systems.

الإحصائيات

The average throughput of the authors' implementation of MINBFT is 6.5 requests/s with 1 client and 55 requests/s with 20 clients.

اقتباسات

"TOLERANCE is a control architecture for intrusion-tolerant systems with two levels of control. On the local level node controllers perform intrusion recovery, and on the global level a system controller manages the replication factor."
"We prove that the optimal control strategies on both levels have threshold structure and design efficient algorithms for computing them."
"The results show that TOLERANCE can achieve higher service availability and lower operational cost than state-of-the-art intrusion-tolerant systems."

الرؤى الأساسية المستخلصة من

Intrusion Tolerance for Networked Systems through Two-Level Feedback Control

by Kim Hammar,R... في arxiv.org 04-03-2024

https://arxiv.org/pdf/2404.01741.pdf

استفسارات أعمق

How can TOLERANCE be extended to provide confidentiality in addition to availability and integrity

To extend TOLERANCE to provide confidentiality in addition to availability and integrity, we can incorporate encryption techniques and access control mechanisms. By encrypting the communication channels between nodes and clients, we can ensure that data remains confidential and secure from eavesdroppers. Additionally, implementing role-based access control and encryption of data at rest can further enhance the confidentiality of the system. By integrating these security measures, TOLERANCE can offer a comprehensive security solution that protects the confidentiality, availability, and integrity of the system.

What are the limitations of the hybrid failure model assumed in this work, and how could the architecture be adapted to handle other failure models

The hybrid failure model assumed in this work has certain limitations, primarily in its assumptions about the behavior of nodes in the system. One limitation is that it assumes nodes can fail arbitrarily but are equipped with trusted components that fail by crashing. This may not always reflect the real-world behavior of nodes, as failures can be more complex and varied. To adapt the architecture to handle other failure models, such as Byzantine or crash-stop failures, the system could incorporate additional monitoring mechanisms and fault detection algorithms. By expanding the fault tolerance mechanisms to accommodate different failure models, the system can be more robust and resilient to a wider range of potential failures.

What are the potential applications of the two-level feedback control approach beyond intrusion-tolerant systems, e.g., in other distributed or cyber-physical systems

The two-level feedback control approach used in TOLERANCE for intrusion-tolerant systems can have applications beyond just security systems. In distributed systems, this approach can be utilized for resource management, load balancing, and fault tolerance. By implementing local and global control mechanisms, systems can adapt dynamically to changing conditions and optimize performance. In cyber-physical systems, the two-level feedback control can be applied to manage energy consumption, optimize processes, and ensure system stability. The flexibility and adaptability of this control architecture make it suitable for a wide range of applications where real-time decision-making and system optimization are crucial.