• Journal of KIISE:Computing Practices and Letters
• /
• v.16 no.3
• /
• pp.331-335
• /
• 2010

Previous low-energy time synchronization methods have mainly focused on reducing the number of transmission or reception packets. However, this paper proposes a method that reduces the percentage of time a node has to be awake (the duty cycle), assuming that a periodic sleep-wake cycle is used to conserve energy. Based on our experience with actual WSN devices, a system model is proposed, and the potential performance of the proposed method, with different parameter values, is analyzed. To further demonstrate the feasibility of our method, experiments were conducted using nine WSN devices in a $3{\times}3$ grid network topology. The results show the average synchronization error is 107.57 $\mu{s}$ in duty cycle 5% and synchronization period 10 sec, and 130 $\mu{s}$ in duty cycle 2.5% and synchronization period 20 sec.

• Journal of KIISE:Computing Practices and Letters
• /
• v.11 no.4
• /
• pp.312-333
• /
• 2005

SIP(Session Initiation Protocol) has been proposed for session control protocol of Internet multimedia communication system like VoIP(Voice over IP). SIP has complicated session control steps to support various kinds of audio and video formats and to assure service quality of real time data communication. Up until now, existing protocol analyzers can not provide such detailed information of SIP based communication system. In this paper, therefore, we propose a new protocol analyzer as a tool that can analyze and diagnose SIP based multimedia communication system throughout the session initiation, data exchange and session change steps. The propose traffic analyzer, which is called STAT(SIP based Traffic Analysis Tool), Is implemented on Winder's environment so that it is generally usable and extensible. Since STAT analyze low level packets captured via Ethernet broadcasting property, it is able to provide session status and real time traffic monitoring information without any affection to the communication system. The STAT which is implemented in this paper. therefore, is expected to be a useful tool for developing and managing of a SIP based multimedia communication system.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.4
• /
• pp.477-485
• /
• 2019

As the drones industry evolved, the security of the drone network has been important. In this paper, MTD (Moving Target Detection) technique is applied to the drone network for improving security. The existing MTD scheme has a risk that the hash value is exposed during the wireless communication process, and it is restricted to apply the one-to-many network. Therefore, we proposed PHT (Preposition Hash Table) scheme to prevent exposure of hash values during wireless communication. By reducing the risk of cryptographic key exposure, the use time of the cryptographic key can be extended and the security of the drone network will be improved. In addition, the cryptographic key exchange is not performed during flight, it is advantageous to apply PHT for a swarm drone network. Through simulation, we confirmed that the proposed scheme can contribute to the security of the drone network.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.32 no.6
• /
• pp.1171-1181
• /
• 2022

Front Collision-Avoidance Assist (FCA) or Smart Cruise Control (SCC) is installed in a modern vehicle, and the amount of data exchange between ECUs increases rapidly. Therefore, Automotive Ethernet, especially SOME/IP, which supports wide bandwidth and two-way communication, is widely adopted to overcome the bandwidth limitation of traditional CAN communication. SOME/IP is a standard protocol compatible with various automobile operating systems, and improves connectivity between components in the vehicle. However, no encryption or authentication process is defined in the SOME/IP protocol itself. Therefore, there is a need for a security study on the SOME/IP protocol. This paper proposes a deep learning-based intrusion detection system in SOME/IP and performs six attacks to confirm the performance of the intrusion detection system.

• Journal of KIISE:Information Networking
• /
• v.35 no.6
• /
• pp.521-528
• /
• 2008

Such conventional maritime communication technologies as radio have short some comings in their transmission quality. It can be overcome by wireless channels provided by satellites such as INMARSAT, which nevertheless suffer from the high costs. In this paper, we propose a novel technology resolving the above problems, featuring in the establishment of maritime communication networks with multi-hop structures. The inter vessel and ship-to- shore networks previously modeled after MANET are remodeled by SANET (Ship Ad Hoc Networks) in the present work. Fan-shaped Search Zone Routing (FSR) protocol also is presented, which utilizes not only static geographical information including the locations of ports and the navigations of courses but also the unique characteristics of ships in terms of mobile nodes. The FSR finds the fan-shaped search zone on which the shortest path is located. The performance of LAR protocol is compared with that of FSR in several ways. First, FSR does not make use of a type of control packets as beaconing data, resulting in a full utilization of the bandwidth of the wireless channels. Second, the delivery rate by the FSR is 100% for the fan-shaped search zone includes at least one route between source and destination nodes on its border line, where as that of LAR has been turned out to be 64%. Third, the optimality of routes searched by the FSR is on a 97% level. Of all, the FSR shows a better performance than LAR by about 50%.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.3
• /
• pp.179-186
• /
• 2013

PACS is a medical system for digital medical images, and PACS expand to web-based service using public network, DICOM files should be protected from the man-in-the-middle attack because they have personal medical record. To solve the problem, we designed flexible secure transmission system using IPSec and adopted to a web-based three-dimensional medical image system. And next, we performed the performance evaluation changing integrity and encryption algorithm using DICOM volume dataset. At that time, combinations of the algorithm was 'DES-MD5', 'DES-SHA1', '3DES-MD5', and '3DES-SHA1, and the experiment was performed on our test-bed. In experimental result, the overall performance was affected by encryption algorithms than integrity algorithms, DES was approximately 50% of throughput degradation and 3DES was about to 65% of throughput degradation. Also when DICOM volume dataset was transmitted using secure transmission system, the network performance degradation had shown because of increased packet overhead. As a result, server and network performance degradation occurs for secure transmission system by ensuring the secure exchange of messages. Thus, if the secure transmission system adopted to the medical images that should be protected, it could solve server performance gradation and compose secure web PACS.

• Journal of KIISE:Information Networking
• /
• v.32 no.6
• /
• pp.659-667
• /
• 2005

A Mobile Ad Hoc Network(MANET) is a multi hop wireless network with no prepared base stations or centralized administrations, where flocks of peer systems gather and compose a network. Each node operates as a normal end system in public networks. In addition to it, a MANET node is required to work as a router to forward traffic from a source or intermediate node to others. Each node operates as a normal end system in public networks, and further a MANET node work as a router to forward traffic from a source or intermediate node to the next node via routing path. Applications of MANET are extensively wide, such as battle field or any unwired place; however, these are exposed to critical problems related to network management, node's capability, and security because of frequent and dynamic changes in network topology, absence of centralized controls, restricted usage on network resources, and vulnerability oi mobile nodes which results from the special MANET's character, shared wireless media. These problems induce MANET to be weak from security attacks from eavesdropping to DoS. To guarantee secure authentication is the main part of security service In MANET because networks without secure authentication are exposed to exterior attacks. In this paper, a multistage authentication strategy based on CGSR is proposed to guarantee that only genuine and veritable nodes participate in communications. The proposed authentication model is composed of key manager, cluster head and common nodes. The cluster head is elected from secure nodes, and key manager is elected from cluster heads. The cluster head will verify other common nodes within its cluster range in MANET. Especially, ID of each node is used on communication, which allows digital signature and blocks non repudiation. For performance evaluation, attacks against node authentication are analyzed. Based on security parameters, strategies to resolve these attacks are drawn up.

• Journal of the Korea Society of Computer and Information
• /
• v.26 no.1
• /
• pp.135-146
• /
• 2021

VMP(Variable Message Protocol) is bit-based variable message processing protocol that enables the sharing situation information in real time as a tactical datalink protocol for Korean Army. System A is currently under development and will be operated as an army system when its development is completed. In system A, the VMP processing terminal is mounted and the VMP is utilized for exchanging tactical information. System A can acquire situation information from mounted situation information acquisition system and share situation information with other system A by the VMP. In this paper, we propose a method of sharing situation information with system A and speed improvement methods of sharing situation information using VMP. As speed improvement methods of sharing situation information, this paper studied 'Removing Process of Sending VMP Observation Report', 'Adopting One-time Situation Information Send Button When Sharing A System Situation Information By VMP', 'Combination of Many VMP Messages Using Repeat Function Of Application Header'. And we conducted the experiment, the result was that the transmission speed of equipment to which the research method was applied was improved by 76.8% compared to the existing equipment.

• Journal of Advanced Navigation Technology
• /
• v.26 no.6
• /
• pp.496-503
• /
• 2022

In the reality that the fishing population is decreasing and the single-man fishing vessels is increasing, mandatory equipment for navigation and radio equipments for the safety of fishing boats has continued to be added. Therefore, many equipment such as navigation, communication and fishing are installed in the narrow steering room, so it is very confusing and a number of monitors are placed in the front, which is a factor that degrades the function of maritime observation. To solve this problem, we studied an interface that integrates and operates to major radio facilities such as very high frequency-digital selective calling equipment (VHF-DSC), automatic identification system (AIS) and fishing boat location transmission device (V-pass) into one multi function display (MFD) based on LAN. In addition, IEC61162-450 UDP packets and IEC61162 sentence were applied to exchange data through link between MFD and radio equipments, and additional messages needed for each equipment and function were defined. The integrated MFD monitor is easily operated by the menu method, and the performance of the interface was evaluated by checking the distress and emergency communication functions related to maritime safety and the message transmission status by equipment.