Xuan Hung Le

Secured WSN-Integrated Cloud Computing for u-Life Care

This paper presents a Secured Wireless Sensor Network-integrated Cloud computing for u-Life Care (SC3). SC3 monitors human health, activities, and shares information among doctors, care-givers, clinics, and pharmacies in the Cloud, so that users can have better care with low cost. SC3 incorporates various technologies with novel ideas including; sensor networks, Cloud computing security, and activities recognition.

An Efficient Mutual Authentication and Access Control Scheme for Wireless Sensor Networks in Healthcare

Wireless sensor networks (WSNs) will play an active role in the 21th Century Healthcare IT to reduce the healthcare cost and improve the quality of care. The protection of data confidentiality and patient privacy are the most critical requirements for the ubiquitous use of WSNs in healthcare environments. This requires a secure and lightweight user authentication and access control. Symmetric key - based access control is not suitable for WSNs in healthcare due to dynamic network topology, mobility, and stringent resource constraints. In this paper, we propose a secure, lightweight public key - based security scheme, Mutual Authentication and Access Control based on Elliptic curve cryptography (MAACE). MAACE is a mutual authentication protocol where a healthcare professional can authenticate to an accessed node (a PDA or medical sensor) and vice versa. This is to ensure that medical data is not exposed to an unauthorized person. On the other hand, it ensures that medical data sent to healthcare professionals did not originate from a malicious node. MAACE is more scalable and requires less memory compared to symmetric key-based schemes. Furthermore, it is much more lightweight than other public key-based schemes. Security analysis and performance evaluation results are presented and compared to existing schemes to show advantages of the proposed scheme.

Activity-oriented access control to ubiquitous hospital information and services

In hospital information systems, protecting the confidentiality of health information, whilst at the same time allowing authorized physicians to access it conveniently, is a crucial requirement. The need to deliver health information at the point-of-care is a primary factor to increase healthcare quality and cost efficiency. However, current systems require considerable coordination effort of hospital professionals to locate relevant documents to support a specific activity. This paper presents a flexible and dynamic access control model, Activity-Oriented Access Control (AOAC), which is based on user activity to authorize access permissions. A user is allowed to perform an activity if he/she holds a number of satisfactory attributes (i.e. roles, assignments, etc.) under a specified condition (e.g. time, location). Results of AOAC implementation in a realistic healthcare scenario have shown to meet two important requirements: protecting confidentiality of health information by denying an unauthorized access, and allowing physicians to conveniently browse medical data at the point-of-care. Furthermore, the average execution time was 0.078s which allows AOAC to work in real-time.

An energy-efficient access control scheme for wireless sensor networks based on elliptic curve cryptography

For many mission-critical related wireless sensor network applications such as military and homeland security, users access restriction is necessary to be enforced by access control mechanisms for different access rights. Public key-based access control schemes are more attractive than symmetric-key based approaches due to high scalability, low memory requirement, easy key-addition/revocation for a new node, and no key pre-distribution requirement. Although Wang et al. recently introduced a promising access control scheme based on elliptic curve cryptography (ECC), it is still burdensome for sensors and has several security limitations (it does not provide mutual authentication and is strictly vulnerable to denial-of-service (DoS) attacks). This paper presents an energy-efficient access control scheme based on ECC to overcome these problems and more importantly to provide dominant energy-efficiency. Through analysis and simulation based evaluations, we show that the proposed scheme overcomes the security problems and has far better energy-efficiency compared to current scheme proposed by Wang et al.

Polarization-based cooperative directional MAC protocol for ad hoc networks

Numerous directional medium access control (DMAC) protocols have been developed to enhance the capacity of ad hoc networks using the underlying advanced physical layer techniques, such as beam-forming, multiuser detection (MUD), and multiple-input-multiple-output (MIMO). In this paper, we propose an innovative fully distributed DMAC protocol that cooperatively makes use of polarization diversity in low-mobility urban/suburban outdoor wireless ad hoc network environment. In the proposed cooperative polarization DMAC protocol (CPDMAC), each node directionally senses on both vertical and horizontal polarizations and dynamically adapts polarization that minimizes overall interference in the ad hoc network. Analysis is performed to establish relationship between vertically and horizontally polarized nodes in the network. Further, a theoretical lower bound is derived for probability of successful transmission to show capacity improvement as a function of cross polarization ratio (CPR). Simulation results confirm from 2% up to 400% improvement in average node throughput at data rate of 1.95Mbps when compared to the traditional DMAC protocol. Moreover, our study clearly shows that the average throughput difference increases with increasing node density when compared to the traditional DMAC protocol.

Visualizations of human activities in sensor-enabled ubiquitous environments

Sensor network ubiquitous environments may generate a lot of data including heterogeneous ‘raw’ sensor data, low-level feature and/or trend data and higher-level context and inferenced information. This paper considers the visualization of such large, heterogeneous and complex integrated information, especially for real-time deployments facilitating rapid understanding leading to decision making. Visualizations are contextually structured according to the newly proposed Serviceable Visualizations paradigm for service-based and cloud-enabled visualizations. Specific visualizations of human activities are subsequently developed. These visualizations are based on the data provided via a secured WSN-integrated Cloud Computing for u-Health Care (SC3) architecture that is under development.

ADMAC with Integrated Destination Discovery for Ad Hoc Networks

Directional antennas have shown to increase spatial reuse by allowing multiple transmitters and receivers to concurrently communicate using directional beams as long as they do not significantly interfere with each other. This appreciably increases average aggregate throughput of the network. Generally, for high throughput performance the directional MAC (Medium Access Control) protocols choose a random direction for destinations location and subsequent data transmissions. Under situations of heavy load, high mobility and narrow beam-width, frequent updates are required to track the destinations. However, frequent updates may degrade the effective throughput of the network. Hence, we propose a novel Adaptive Directional MAC (ADMAC) protocol with integrated destination discovery that estimates destinations possible search span and then initiates transmission in that search span direction. Another major contribution is the average throughput performance comparison between last sector (LS), random sector (RS) and search span approaches. Average throughput results show an improvement of up to 40 % and greater than 400 %, when compared to the LS and the RS based DMAC protocols, respectively.

Performance Evaluation of Quick-Start in Low Latency Networks

The Quick-Start mechanism has been presented as a way for transport control protocols to efficiently use available bandwidth in under-utilized networks. Although studies of performance of Quick-Start have been carried out, its performance in low latency networks has not been well investigated. In this paper, we show that the benefits of Quick-Start in low latency networks are minimal. We also show that the improvement in network utilization is much lower than in networks with higher latencies. Our future work in this field will undoubtedly lead to new algorithms and improvements to existing ones.