Medical Cyber-Physical Systems Development: A Forensics-Driven Approach

Abstract: The synthesis of technology and the medical industry has partly contributed to the increasing interest in Medical Cyber-Physical Systems (MCPS). While these systems provide benefits to patients and professionals, they also introduce new attack vectors for malicious actors (e.g. financially-and/or criminally-motivated actors). A successful breach involving a MCPS can impact patient data and system availability. The complexity and operating requirements of a MCPS complicates digital investigations. Coupling this information with the potentially vast amounts of information that a MCPS produces and/or has access to is generating discussions on, not only, how to compromise these systems but, more importantly, how to investigate these systems. The paper proposes the integration of forensics principles and concepts into the design and development of a MCPS to strengthen an organization's investigative posture. The framework sets the foundation for future research in the refinement of specific solutions for MCPS investigations.

• The paper demonstrates that embedding forensic principles from the design phase enhances MCPS incident response capabilities.
• It introduces a risk assessment and forensic-readiness framework addressing security, privacy, and legal compliance concerns in complex medical systems.
• The proposed approach is validated through rigorous testing protocols for evidentiary data collection, ensuring reliability and admissibility in investigations.

Medical Cyber-Physical Systems Development: Forensics-Driven Approach

Introduction

The paper "Medical Cyber-Physical Systems Development: A Forensics-Driven Approach" (1708.05374) investigates the integration of forensic principles into the development of Medical Cyber-Physical Systems (MCPS). These systems, which merge technology and medical fields, present unique security and forensic challenges due to their complexity and the sensitive nature of the data they handle. The proposed framework aims to bolster the forensic readiness of MCPS to facilitate effective investigations post-security incidents, suggesting that forensic principles be embedded into the system development lifecycle.

Challenges and Motivation

MCPS are distinguished by their interconnected nature, often comprising multiple medical devices integrated with network interfaces that synchronize with Electronic Health Records (EHRs). Such integration, while beneficial, introduces potential vulnerabilities that malicious actors could exploit, raising significant concerns about system reliability and patient safety. These systems often require novel design strategies, such as interoperability and context-awareness, and must balance stringent safety certifications with privacy and security demands.

Additionally, due to the sheer volume of data a MCPS manages, traditional post-incident investigations can be cumbersome and inefficient. The need for forensic readiness is underscored by the potential impact of breaches on system availability and patient data, which could lead to severe consequences, including loss of life.

Forensic-Driven Framework

The proposed forensic-by-design framework comprises multiple components aimed at integrating forensic readiness into MCPS. The approach ensures that MCPS development considers potential evidential data from the outset, with emphasis on the following elements:

1. Risk Assessment: Identifying and prioritizing threats and vulnerabilities to guide forensic readiness strategies.
2. Forensic Readiness Principles: Aligning systems with forensic objectives, identifying potential evidence sources, and establishing data handling protocols.
3. Security and Privacy Requirements: Ensuring systems are robust against threats while preserving patient confidentiality during forensic investigations.
4. Legislative and Regulatory Compliance: Systems must comply with relevant health care laws and standards, particularly those affecting data handling and privacy.
5. Medical and Safety Requirements: Balancing forensic needs with medical functionalities, ensuring patient safety remains a priority despite forensic integration.
6. Hardware and Software Considerations: Addressing interoperability challenges and ensuring all MCPS layers can support forensic investigations without compromising system integrity.

Forensic-Readiness Testing

To validate a system's forensic capabilities, the paper suggests rigorous testing against pre-defined forensic requirements. This includes ensuring that evidential data is accurately captured and stored under evidentiary standards, is retrievable under investigation conditions, and adheres to the Daubert standard for legal admissibility. Establishing error rates through repeated testing is critical for ensuring the reliability of evidential data acquisition and handling.

Implications and Future Work

The proposed framework endeavors to preemptively address investigative challenges, suggesting that forensic readiness should be a standardized component of MCPS development. By doing so, it enhances the ability to effectively respond to incidents, ultimately safeguarding patient data and system availability.

Future work as described involves refining the proposed framework through practical implementations, ideally in hospital test-beds, to validate and adjust the framework to real-world settings. The ongoing evolution and complexity of MCPS suggest that forensic readiness will remain a critical area of research, essential for advancing the security and reliability of these life-critical systems.

Conclusion

This forensic-driven approach lays the groundwork for integrating investigative capabilities into the MCPS development process. By embedding forensic principles early in the lifecycle, the framework aims to enhance both the resilience and investigatory readiness of medical systems, ensuring that they are equipped to respond effectively to security incidents while safeguarding critical medical functionalities.