An Integrated Real-Time and Security Scheduling Framework for CPS

In the world of real-time systems (RTS), security has often been overlooked in the design process. However, with the emergence of the Internet of Things and Cyber-Physical Systems, RTS are now frequently used in interconnected applications where data is shared regularly. Unfortunately, this increased connectivity has also led to a larger attack surface. As a result, it is crucial to redesign RTS to not only meet real-time requirements but also to be resilient to threats. To address this issue, we propose a new real-time security co-design task model, and an accompanying scheduling framework, where schedulability can be used to indicate whether both real-time and security requirements are met. Our algorithm is designed to be flexible, allowing different security mechanisms to be used along with real-time tasks. Specifically, we augment the frame-based task model by introducing an n-dimensional security matrix, which serves as a powerful tool to enable our approach. This matrix clearly indicates which defense mechanisms are available for each task in the system by storing the worst-case execution times of tasks. Then, we transform the problem of maximizing security, subject to schedulability, into a variant of the knapsack problem. To make this approach more practical, we implement a fully polynomial time approximation scheme (FPTAS) that reduces the time complexity of solving the knapsack problem from a pseudo-polynomial to a fully polynomial. We also experiment with a greedy-heuristic approach and compare the results of both algorithms.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Computer Engineering

Department dc:contributor.department

Electrical and Computer Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2023

Author dc:creator

• Kansal, Kriti

Chair dc:contributor.committeechair

• Chantem, Thidapat

Committee members dc:contributor.committeemember

• Wang, Yue J.
• Min, Chang Woo

• Real-time systems
• Security
• Scheduling
• Resilience

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:37289

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/115098