Jyh-How Huang

A Level Key Infrastructure for Secure and Efficient Group Communication in Wireless Sensor Network

Group communication to and from sets of sensor nodes is an important paradigm in wireless sensor networks (WSNs). Securing this group communication is a difficult challenge given the energy-efficiency constraints posed by WSNs. In this paper, we introduce the protocol SLIMCAST, i.e. Secure Level key Infrastructure for MultiCAST and group communication, which uses level keys to provide an infrastructure that dramatically lowers the cost of nodes joining and leaving sensor groups. This level key infrastructure is shown to achieve energyefficient key updates that are localized for group multicast 1→N communication, and can be further leveraged to achieve secure group aggregation N→1 communication. Simulation results comparing the performance of SLIMCAST to traditional secure group communication protocols are presented to demonstrate SLIMCAST’s energy efficiency and flexibility.

Mykil: a highly scalable key distribution protocol for large group multicast

This paper describes the design, implementation, and evaluation of Mykil, which is a new key distribution protocol for secure group multicast. Mykil has been designed to be scalable to large group sizes. It is based on a combination of group-based hierarchy and key-based hierarchy systems for group key management. Important advantages of Mykil include a fast rekeying operation for large group sizes, continuous availability of the key management service in a disconnected network environment, an ability to map the group structure to the underlying network infrastructure, robustness, support for user mobility, and support for smaller hand-held devices.

A sensor based tracking system using witnesses

Search and rescue of people in emergency situations, e.g. lost hikers, stranded climbers, or injured skiers has been difficult due to lack of information about their location at various times. Current location and tracking systems require a connected network via satellites, GSM base stations, or mobile devices. This requirement severely limits their applicability, particularly in remote wilderness areas where maintaining a connected network is very difficult. This paper proposes a new tracking system called Cenwits that is based on sensors that use RF for communication and emit beacons from time to time. When two sensors are in the range of one another, they record the presence of each other and exchange the information they recorded earlier. A sensor dumps all its information to an access point, whenever it is in the range of one. Important advantages of Cenwits include a loosely-coupled system that does not require network connectivity, power efficiency, and low cost. A preliminary prototype of Cenwits is being built using Berkley Mica2 Motes. The paper reports results from this preliminary prototype.

Support for mobility and fault tolerance in Mykil

This paper describes the support provided for mobility and fault tolerance in Mykil, which is a key distribution protocol for large, secure group multicast. Mykil is based on a combination of group-based hierarchy and key-based hierarchy systems. Important advantages of Mykil include a fast and efficient rekeying operation for large group sizes, continuous availability of the key management service in a disconnected network environment, an ability to map group structure to the underlying network infrastructure, fault tolerance, and support for member mobility and smaller hand-held devices.

A Security Framework for SenSearch

We have described the design and a preliminary prototype implementation of a security and privacy framework for SenSearch, which is a search and rescue system for locating people in emergency situation in wilderness areas. Security and privacy is extremely important in such systems, because they collect location and movement information about a person. Our framework carefully employs both symmetric and asymmetric key cryptography. Preliminary performance measurements show that our framework is feasible and provides the required support for security and privacy.

Security and Privacy in a Sensor-Based Search and Rescue System

With the emergence of small devices equipped with wireless communication, several sophisticated systems for search and rescue have been proposed and developed. However, a key obstacle in large deployment of these systems is vulnerability to users’ security and privacy. On one hand, search and rescue systems need to collect as much information about a user’s location and movement as possible to locate that user in a timely manner. On the other hand, this very capability can be misused by adversaries to stalk a person, which in turn drives users away from using such a system. This paper describes the design, implementation and performance of a security and privacy framework for SenSearch, which is a sensor-based search and rescue system for people in emergency situation in wilderness areas. This framework has been carefully built by employing a combination of symmetric and asymmetric key cryptography to meet the constraints of resource-limited devices and short time intervals during which most security operations have to be performed.

Mykil: a secure and highly available key management system for large group multicast

Abstract This paper describes the design, implementation and evaluation of Mykil, a new key management system for supporting secure group multicast. Mykil was developed on a combination of group-based hierarchy and key-based hierarchy systems for secure group key management. The advantages of Mykil include a fast and efficient rekeying operation for large group sizes, continuous availability of the key management service in a disconnected network environment, an ability to map group structure to the underlying network infrastructure, and support for user mobility and smaller, hand-held devices. A prototype of Mykil has been implemented. The paper describes this implementation and reports on the performance measured.