• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.2
• /
• pp.946-959
• /
• 2018

Recently interest in Internet of Things(IoT) has attracted significant attention at national level. IoT can create new services as a technology to exchange data through connections among a huge number of objects around the user. Data communication between objects provides not only information collected in the surrounding environment but also various personalized information. IoT services which provide these various types of data are exposed to numerous security vulnerabilities. If data is maliciously collected and used by an attacker in an IoT environment that deals with various data, security threats are greater than those in existing network environments. Therefore, security of all data exchanged in the IoT environment is essential. However, lightweight terminal devices used in the IoT environment are not suitable for applying the existing encryption algorithm. In addition, IoT networks consisting of many sensors require group communication. Therefore, this paper proposes a secure multicast scheme using the proxy re-encryption method based on Vehicular ad-hoc networks(VANET) environment. The proposed method is suitable for a large-scale dynamic IoT network environment using unreliable servers.

• Information and Communications Magazine
• /
• v.24 no.9
• /
• pp.86-95
• /
• 2007

사무실과 가정의 컴퓨터, 대중화된 휴대폰 사용 그리고 인터넷으로 특징지어지는 정보통신 기술덕택에 현대인은 어느 정도 시간과 공간의 제약을 극복하고 있다. 그러나, 아직도 현대인은 예전에 비해 가까워진 지구촌을 여러 가지 이동체를 타고 이동을 하여야한다. 특히 현대인에게 있어서 자동차는 가정과 직장을 이어주고 업무 목적지와 휴식을 위한 휴양지를 찾아가기 위한 실질적인 이동 수단으로서 가정과 직장에 이은 또 하나의 정보통신기술이 필요한 중요한 영역이다. 따라서 미래형 자동차는 편의 주행, 쾌적 주행을 제공하고 그리고 안전 주행이 보장되는 지능형 자동차의 수요가 예견되고 있으며 이를 구현하기위해 첨단 정보통신, 전자, 제어기술이 요구되고 있다. [1][5][6] 이상과 같은 지능형 자동차 관련 응용 분야는 위 그림과 같이 자동차 여러 부위에 장착되는 첨단 전장품들에 의해서 구현이 된다. 그러나, 기존의 자동차와 달리 미래형 지능형 자동차에서는 많은 전장품들이 장착됨에따라 소요되는 전원의 용량이 증가하게되어 기존 12V에서 42V 시스템으로 바뀔 예정이다. 또한 각종 센서로부터 정보신호를 받아서 정보처리를 하고 Actuator를 제어하기 위해서 많은 전장품들간에 연결되는 신호선들의 배선이 복잡해짐에따라 생산부서에서의 공정비용이 증가하게된다. 또한 향후 석유 에너지의 고갈에 따른 전기 자동차로의 전환이 예상되는데 위에서 언급된 많은 전자장치들간 신호를 주고 받기위해 차량내 여러부위로 퍼져있는 배선들이 차지하는 무게가 상당하므로 차체의 무게를 가볍게 해야하는 차세대 전기 자동차의 성능 향상을 위해서 효율적인 In Vehicular Network 기술이 요구된다. 또한 향후 자동차에 장착된 많은 전자장치들의 고장 진단 및 내장된 SW를 효율적으로 갱신하기 위해서는 여러 전자장치들이 하나의 버스로 연결되는 In Vehicle network이 필수적이다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.2
• /
• pp.542-558
• /
• 2016

Vehicular Ad Hoc Networks (VANETs) are self-configuring networks where the nodes are vehicles equipped with wireless communication technologies. In such networks, limitation of signal coverage and fast topology changes impose difficulties to the proper functioning of the routing protocols. Traditional Mobile Ad Hoc Networks (MANET) routing protocols lose their performance, when communicating between vehicles, compromising information exchange. Obviously, most applications critically rely on routing protocols. Thus, in this work, we propose a methodology for investigating the performance of well-established protocols for MANETs in the VANET arena and, at the same time, we introduce a routing protocol, called Genetic Network Protocol (G-NET). It is based in part on Dynamic Source Routing Protocol (DSR) and on the use of Genetic Algorithms (GAs) for maintenance and route optimization. As G-NET update routes periodically, this work investigates its performance compared to DSR and Ad Hoc on demand Distance Vector (AODV). For more realistic simulation of vehicle movement in urban environments, an analysis was performed by using the VanetMobiSim mobility generator and the Network Simulator (NS-3). Experiments were conducted with different number of vehicles and the results show that, despite the increased routing overhead with respect to DSR, G-NET is better than AODV and provides comparable data delivery rate to the other protocols in the analyzed scenarios.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.4 no.1
• /
• pp.42-49
• /
• 2009

Most Vehicular Ad hoc Network (VANET) applications rely heavily on broadcast transmission of traffic related information to all reachable nodes within a certain geographical area. Among various broadcast approaches, flooding is the first broadcasting technique. Each node rebroadcasts the received message exactly once, which results in broadcast storm problems. Some mechanisms have been proposed to improve flooding in Mobile Ad hoc Networks (MANET), but they are not effective for VANET and only a few studies have addressed this issue. We propose two distance-based and timer-based broadcast suppression techniques: 15P(15percent) and slotted 15P. In the first (distance based) scheme, node's transmission range is divided into three ranges (80%,15%and5%). Only nodes within 15% range will rebroadcast received packet. Specific packet retransmission range (15%) is introduced to reduce the number of messages reforwarding nodes that will mitigate the broadcaststorm. In the second (timer-based) scheme, waiting time allocation for nodes within 15% range isused to significantly reduce the broadcaststorm. The proposed schemes are distributed and reliedon GPS information and do not requireany other prior knowledge about network topology. To analyze the performance of proposed schemes, statistics such as link load and the number of retransmitted nodes are presented. Our simulation results show that the proposed schemes can significantly reduce link load at high node densities up to 90 percent compared to a simple broadcast flooding technique.

• International journal of advanced smart convergence
• /
• v.11 no.2
• /
• pp.7-12
• /
• 2022

Safety and security are the topmost priority in every environment. With the aid of Artificial Intelligence (AI), many objects are becoming more intelligent, conscious, and curious of their surroundings. The recent scientific breakthroughs in autonomous vehicular designs and development; powered by AI, network of sensors and the rapid increase of Internet of Things (IoTs) could be utilized in maintaining safety and security in our environments. AI based on deep learning architectures and models, such as Deep Neural Networks (DNNs), is being applied worldwide in the automotive design fields like computer vision, natural language processing, sensor fusion, object recognition and autonomous driving projects. These features are well known for their identification, detective and tracking abilities. With the embedment of sensors, cameras, GPS, RADAR, LIDAR, and on-board computers in many of these autonomous vehicles being developed, these vehicles can properly map their positions and proximity to everything around them. In this paper, we explored in detail several ways in which these enormous features embedded in these autonomous vehicles, such as the network of sensors fusion, computer vision and natural image processing, natural language processing, and activity aware capabilities of these automobiles, could be tapped and utilized in safeguarding our lives and environment.

• Journal of Communications and Networks
• /
• v.6 no.4
• /
• pp.295-306
• /
• 2004

In this paper, a novel air-interface is presented for Fleet-Net1, a self-organizing network for inter-vehicle and vehicle-toroadsidecommunication. The air-interface is based upon the lowchip-rate version of UMTS/TDD. To adapt the cellular UMTS standard to an air-interface for ad hoc networks, changes of the physical layer, medium access control sub-layer and radio resource management are required. An overview of the required modifications is given here. Particularly, a decentralized synchronization mechanism is presented and analyzed by means of simulations. Furthermore, changes for the medium access control are explained in detail, which allow for an efficient operation in partly meshed networks and prioritization. Performance results of the overall system considering throughput and delay are derived by means of analytical evaluations and event-driven simulations. Based on realistic mobility models, it is shown that the presented solution provides a robust communication platform even in vehicular environments. The proposed air-interface is a cost-effective solution not only for inter-vehicle communication, but also for ad hoc networking in general, benefiting from the mass-market of UMTS.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.5B
• /
• pp.849-857
• /
• 2010

Security is essential to make use of application service securely in VANET environments. This paper proposes payment protocol which supports user's anonymity. The proposed protocol is designed to use a charge card as a payment method and performs pre-registration, renewal and payment phase. The user's anonymity and disclosure of charge card information is protected through the pre-registration and renewal phase, and also fast computing operation is supported by minimizing the computational load on vehicles.

• Journal of Communications and Networks
• /
• v.11 no.6
• /
• pp.607-614
• /
• 2009

Recently, Lu et al. proposed an efficient conditional privacy preservation protocol, named ECPP, based on group signature scheme for generating anonymous certificates from roadside units (RSUs). However, ECPP does not provide unlinkability and traceability when multiple RSUs are compromised. In this paper, we make up for the limitations and propose a robust and efficient anonymous authentication protocol without loss of efficiency as compared with ECPP. Furthermore, in the proposed protocol, RSUs can issue multiple anonymous certificates to an OBU to alleviate system overheads for mutual authentication between OBUs and RSUs. In order to achieve these goals, we consider a universal re-encryption scheme and identity-based key establishment scheme as our building blocks. Several simulations are conducted to verify the efficiency and effectiveness of the proposed protocol by comparing with those of the existing ECPP.

• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.293-295
• /
• 2009

In an Intelligent Transport System(ITS), data dissemination based on inter-vehicle communication is effective for acquiring real-time traffic-jam information. In this paper, we propose a novel method for traffic jam information dissemination in vehicular ad-hoc networks. In our proposed method, vehicles already trapped in a Traffic-Jam elect leaders according to their locations from upstream and downstream respectively. Then each leader generates traffic data which contains their position, velocity and leader counter respectively, and disseminate the information. {{br}}The implementation of our proposed method is evaluated by means of simulation, and we also present simulation result

• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.201-203
• /
• 2009

In the VANET, density is a most important factor for reception rate of packet. So, we have to find solutions to reduce packet collision. There are two approaches. First, packet collision avoid by controlling transmission interval. Second, packet collision avoid by controlling transmission power. In this paper, we propose a simple method to reduce a packet collision by controlling transmission power. It uses the number of neighbors and adaptive controlling method. This method have better performance about packet reception rate.