Improving the Security of the IEEE 802.15.6 Standard for Medical BANs (2201.06354v4)

Abstract: A Medical Body Area Network (MBAN) is an ensemble of collaborating, potentially heterogeneous, medical devices located inside, on the surface of or around the human body with the objective of tackling one or multiple medical conditions of the MBAN host. These devices -- which are a special category of Wireless Body Area Networks (WBANs) -- collect, process and transfer medical data outside of the network, while in some cases they also administer medical treatment autonomously. Since communication is so pivotal to their operation, the newfangled IEEE 802.15.6 standard is aimed at the communication aspects of WBANs. It places a set of physical and communication constraints while it also includes association/disassociation protocols and security services that WBAN applications need to comply with. However, the security specifications put forward by the standard can be easily shown to be insufficient when considering realistic MBAN use cases and need further enhancements. The present work addresses these shortcomings by, first, providing a structured analysis of the IEEE 802.15.6 security features and, afterwards, proposing comprehensive and tangible recommendations on improving the standard's security.

• The paper demonstrates a heuristic use-case analysis to pinpoint key security vulnerabilities in the IEEE 802.15.6 standard for MBANs.
• It examines scenarios including neural dust, leadless cardiac pacemakers, and artificial pancreas to highlight scalability and authentication challenges.
• The study recommends integrated physical, cryptographic, and authorization upgrades to strengthen secure communications in medical body networks.

Improving the Security of the IEEE 802.15.6 Standard for Medical Body Area Networks (MBANs)

The cybersecurity domain, particularly concerning medical Body Area Networks (MBANs), presents unique challenges due to the sensitive nature of Personal Health Information (PHI) and the critical roles these networks play in treatment and data collection. The IEEE 802.15.6 standard, designed specifically for Wireless Body Area Networks (WBANs), forms a pivotal foundation for securing communication within these networks. However, its current specifications are deemed insufficient to address the evolving security needs of MBANs. This paper evaluates and recommends enhancements to the security protocols of the IEEE 802.15.6, aimed at addressing these insufficiencies using a structured use-case methodology.

Overview of MBANs and IEEE 802.15.6

MBANs deploy a variety of interconnected medical devices, such as sensors and actuators, to monitor and sometimes treat medical conditions in real-time. These devices are classified based on their functionality, implementation, and role within the network. The IEEE 802.15.6 standard outlines the communication protocols at the PHY and MAC layers, offering three security levels ranging from unsecured communication to fully authenticated and encrypted data exchange.

Methodological Approach

The authors propose a heuristic methodology to evaluate and improve the standard's security posture by using representative use cases. The use cases are strategically chosen to span a broad range of security-related attributes. This approach ensures comprehensive coverage, enabling a detailed analysis of potential vulnerabilities without the impracticality of exhaustive testing across the entire design space. The methodology emphasizes real-world applications and factors in realistic constraints and resources of MBAN devices.

Key Findings from Use Case Analysis

Three primary use cases were deliberated:

1. Neural Dust: This use case highlights the challenge of scalable security for a large number of micron-sized, resource-constrained nodes using specialized communication modalities such as ultrasound.
2. Leadless Cardiac Pacemaker (LCP): The feasibility of secure communication in a star-topology network and the integration of multiple implantable devices underscore the need for dynamic association protocols and robust key management mechanisms.
3. Artificial Pancreas: This scenario emphasizes the importance of ensuring secure peer-to-peer communication and demands resilient authorization processes to safeguard against unauthorized access and data manipulation.

These use cases collectively cover all defined security and physical attributes. The analysis reveals several significant security gaps in the IEEE 802.15.6 standard, including insufficient scalability for large networks, inadequate treatment of complex network topologies like peer-to-peer models, and a lack of detailed guidance on mutual authentication processes.

Recommendations for Standard Improvement

The paper provides a set of recommendations, clustered across various domains, to bolster the IEEE 802.15.6 standard:

• Physical and Organizational Enhancements: Address node failures and expand network topology capabilities to include peer-to-peer and multi-hub arrangements for higher reliability and scalability.
• Cryptographic Strengthening: Adopt more robust encryption techniques and diverse key sizes to secure sensitive communications across all network configurations.
• Authentication and Authorization Mechanisms: Incorporate detailed mutual authentication procedures and establish access-control mechanisms to prevent unauthorized node access.
• Defense Against Specific Threats: Implement strategies to mitigate denial-of-service attacks and improve the overall robustness and dependability of MBANs.

Conclusion and Future Directions

This paper’s structured assessment establishes a strong framework for enhancing the security of the IEEE 802.15.6 standard, making it more adaptable to current and future MBAN technologies. The recommendations are crafted to be iterative and extensible, capable of integrating new vulnerabilities and technological advancements over time. Adopting these enhancements could significantly improve the broader adoption and trust in MBAN applications by fortifying privacy and security measures critical to patient safety and data integrity. Future research could focus on refining these security protocols and expanding the assessment methodology to additional standards in related domains.