Yeongkwun Kim

Security issues in vehicular networks

Vehicular ad-hoc networks (VANETs) have become the focus of much discussion due to its potential role in helping to improve traffic management and safety and enable a wide range of value-added services such as collision warning/avoidance and work zone warning. Because information transmitted over a vehicular network is sensitive and can affect important safety decisions, security requirements for VANETs applications prove stringent. Thus, fail-safe security is mandatory. However, providing security in vehicular networks raises important privacy concerns also worth considering. Security and privacy are the two main concerns motivating robust vehicular network designs. In this paper, we will discuss some threats and attacks that can be exploited, and in response, present some viable security solutions.

A taxonomy for DOS attacks in VANET

Vehicular Ad hoc Network (VANET) has become an attractive topic in fields of academia and industry due to its potential role in helping to improve traffic management and safety on the road. The information transmitted over a vehicular network is sensitive and can affect important safety decisions. However, they face various types of security attacks, such as Denial of Service (DOS) attacks. DOS and distributed DOS attacks are a rapidly growing problem and offer an important point of consideration as such attacks do not require the penetration of the target network. In this paper, we explore DOS in VANET to propose taxonomy as a means of identifying the attacker, its capabilities, the target, the type of vulnerability used for attack, and the impact on the victim.

SESAME: space-efficient stack allocation mechanism for multi-threaded sensor operating systems

This paper proposes a SESAME, which is a Space-Efficient Stack Allocation MEchanism for multi-threaded sensor operating systems. It adaptively adjusts the stack size by allocating or releasing additional stack frame based on the amount of each functions stack usage information. Our experimental results show that the SESAME significantly minimizes spatial overhead of threads stacks with tolerable time overhead compared with fixed stack allocation mechanism of the multi-threaded sensor operating systems.

Towards a trust management for VANETs

Information transmitted over a vehicular network may be sensitive and affect important safety decisions. Exchanging information must be based on trust; however, an issue that arises is the degree to which drivers can trust the received information from other (previously unknown) drivers. Thus, trust management is a fundamental and critical issue in vehicular ad-hoc networks (VANETs). However, studies and research have yet to thoroughly address this important problem. In this paper, we offer some discussion on the topic and propose a possible way of building an effective trust management system. Finally, we also present a discussion on the topics of privacy and reputation in VANETs.

Virtual protocol stack interface for multiple wireless sensor network simulators

We present VPSI, which is a Virtual Protocol Stack Interface for wireless network simulators. VPSI provides two features; 1) a unified programming interface for developing network protocols, and 2) separation of simulator engine and the network protocols. By using VPSI, developers do not need to understand multiple different simulator engines. We implemented and adapted VPSI on existing well-known simulation packages, and we observed that VPSI works well with different wireless network simulators.

Arbiter-Recall : a new function update scheme by arbitration between a remote call and a dynamic update for wireless sensor networks

In this paper, we propose Arbiter-Recall, which is a new kind of function code update management. When a function requires updating, Arbiter-Recall adaptively selects an energy-efficient method, deciding between a remote-call and a local-call after updating a function. The run-time decision is made by analyzing the cost of a remote-call, and a local-call with dynamic function update in terms of the energy consumption. Simulation results show that Arbiter-Recall significantly reduces energy consumption compared to existing schemes.

An Efficient and Reliable flooding in MANETs

Flooding has been used in mobile ad-hoc networks (MANETs) because it is the simplest method for broadcasting messages over an entire network. Several reliable and energy-efficient flooding mechanisms have been developed in recent years. However, an appropriate mechanism which considers dynamic topology changes in MANETs has yet to be developed. Thus, in this paper, we propose an efficient and reliable flooding mechanism. The proposed mechanism uses both FPR and BPR (Forward and Backward Packet Recovery) methods to achieve more robust and reliable flooding. The mechanism enables the receivers to recover missed packets by using the redundant packets in FPR and the request packets for retransmission in BPR. Through analytical modeling, we investigate the impact of redundancy and optimal redundancy in terms of the energy-efficiency in FPR and BPR. In order to maximize the reliability while minimizing network overhead, our mechanism dynamically adjusts the redundancy according to network conditions. Simulation results show that our mechanism provides both increased reliability and energy-efficiency compared to the existing flooding mechanisms.

PreeMe: preemptive real-time task management for event-driven sensor operating systems

This paper proposes PreeMe, which is a preemptive realtime task management scheme for event-driven sensor operating systems. By efficiently allocating independent stack space for each task, PreeMe enables the preemptive task management for the event-driven systems. The size of the minimal stack space for each task is determined at compiletime, and dynamic stack allocation is performed at run-time. Simulation results show that PreeMe significantly reduces scheduling latency with small execution overhead.