David Sanchez

Resource-efficient security for medical body sensor networks

Key management is a fundamental service for medical body sensor network (BSN) security. It provides and manages the cryptographic keys to enable essential security services such as confidentiality, integrity and authentication. In the medical context, the design of a key management service must be consistent with the strict operational and security requirements of healthcare as well as with the resource restrictions of BSN technology. The deterministic pairwise key pre-distribution scheme (DPKPS) allows direct pairwise key establishment in sensor networks. We present a consistent key management service for hospital BSNs based on the DPKPS. We also describe a practical implementation specifically adapted to the strict resource-constraints of the popular MICAz sensor platform. Our performance analysis demonstrates that this key management service enables advanced BSN security services at an extremely low-power and low-memory cost

Secure, accurate and precise time synchronization for wireless sensor networks

Secure time synchronization is a key service for wireless sensor networks (WSN). The special nature of WSNs imposes challenging and intertwined requirements on secure time synchronization design. We show that secure time synchronization techniques proposed to date fail to fulfil the security, accuracy, precision and energy-cost required trade-off for WSNs. We propose a novel pairwise and clusterwise-based approach to securely synchronize nodes of a WSN. We develop a meshed network of cluster heads to securely transfer global time among cluster heads. Then, in turn, cluster heads transfer global time to the nodes of each cluster. The analysis in this paper shows that this approach exhibits very advanced security, accuracy, precision and low-energy trade-off. Moreover, this approach can equally be applied to star or peer-to-peer-based clustered WSNs.

Secure Precise Clock Synchronization for Interconnected Body Area Networks

Secure time synchronization is a paramount service for wireless sensor networks (WSNs) constituted by multiple interconnected body area networks (BANs). We propose a novel approach to securely and efficiently synchronize nodes at BAN level and/or WSN level. Each BAN develops its own notion of time. To this effect, the nodes of a BAN synchronize with their BAN controller node. Moreover, controller nodes of different BANs cooperate to agree on a WSN global and/or to transfer UTC time. To reduce the number of exchanged synchronization messages, we use an environmental-aware time prediction algorithm. The performance analysis in this paper shows that our approach exhibits very advanced security, accuracy, precision, and low-energy trade-off. For comparable precision, our proposal outstands related clock synchronization protocols in energy efficiency and risk of attacks. These results are based on computations.