• Journal of KIISE:Databases
• /
• v.36 no.5
• /
• pp.352-365
• /
• 2009

Recently, data access control policies have not been applied for authorized or unauthorized persons properly and information leakage incidents have occurred due to database security vulnerabilities. In the traditional database access control methods, administrators grant permissions for accessing database objects to users. However, these methods couldn't be applied for diverse access control policies to the database. In addition, another database security method which uses data encryption is difficult to utilize data indexing. Thus, this paper proposes an enhanced database access control system via a packet analysis method between client and database server in network to apply diverse security policies. The proposed security system can be applied the applications with access control policies related to specific factors such as date, time, SQL string, the number of result data and etc. And it also assures integrity via a public key certificate and MAC (Message Authentication Code) to prevent modification of user information and query sentences.

• Journal of KIISE:Information Networking
• /
• v.29 no.5
• /
• pp.482-494
• /
• 2002

In E-mail based accounting system, the remitter does not have need to find collector's account number. To transfer money to a collector's account, what remitter need is just a collector's E-mail address. But the current E-mail based accounting systems are built on SSL technology. Basically SSL provides some security services - confidentiality, user authentication and data integrity, but does not provide non-repudiation. So, in the current E-mail based accounting system, it is possible to deny transaction. And there is no receipt of transaction. In this paper, we design and implementation of a S/MIME applied Secure Payment Mechanism. In our system, every account information - account number, receiver name, amount of money, etc. - is included in a 'check' message. And this message is protected under the Secure Web-mail using S/MIME. In a view point of the convenience, users using our system do not have need to find collector's account number. And in a view point of the security, our system provides confidentiality, user authentication, data integrity and non-repudiation. Moreover our system provides a receipt.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.12
• /
• pp.2252-2258
• /
• 2016

CCMP(centralized conferencing manipulation protocol) enables adding and removing conference participants, changing their roles, adding and removing media streams in conference system. In this paper, by using extended CCMP, a new distributed conference system architecture which can be used to multiple servers distributed conference system in SIP(session initiation protocol) environment has been presented. In this study, according to increasing number of participants, a new extended CCMP architecture which can distribute conference system loads to multiple servers dynamically to decrease loads of servers has been designed. This extended CCMP architecture also can add dynamically new servers from the prepared servers pool. Furthermore, new conference information data format which can represent extended CCMP has been designed, and exchange procedures of extended CCMP control messages which can distribute loads between servers have also been presented. The performance of the proposed system has been analysed by simulation.

• The KIPS Transactions:PartC
• /
• v.8C no.4
• /
• pp.421-428
• /
• 2001

위성통신 시스템은 기존의 지상망이나 광 케이블 기술에 비해 통신 대역폭의 유연성과 다중 접속 능력, 이동 통신, 광역성, 멀티포인트 및 브로드캐스팅 등의 고유의 특징으로 인해 초 고속 정보 통신망 구축에 중요한 역할을 할 것이다. 또한 위성통신은 앞으로 도래할 브로드 캐스팅 및 멀티미디어 서비스 등의 통신환경을 지원하며, 지상중계망의 장애 및 트래픽 폭 주시에 대체경로를 제공함으로써 지상망 중심으로 진화·발전되어 온 B-ISDN망과 상호 보 완적인 보완망으로서의 역할을 수행할 것이다. 따라서 지상 B-ISDN과 위성망의 통합은 지 상망의 효율성고 안정성을 향상시킬 수 있을 뿐만 아니라 국가의 모든 통신망을 하나의 정 보 통신망으로 구성하여 국가의 정보를 효율적으로 이용, 관리 및 운용할 수 있기 때문에 위성망과 B-ISDN간의 연동에 대한 연구는 필수적이다. 본 논문에서는 OBP(On-Board Processing) 탑재 위성 B-ISDN 중계망의 호 처리 절차 연구를 수행하는 것으로서, 위성 B-ISDN 구조와 각 지구국별 신호 기능 및 B-ISDN 신호 시스템인 DSS2(Digital Subscriber Signalling No.2) 계층 3 신호 프로토콜, B-ISUP(B-ISDN User Part) 프로토콜, S-BISUP(Satellite BISUP) 프로토콜의 구조를 분석하였다. 또한 점-대-다지점 연결을 위한 B-ISDN의 연결과 소유권 및 각각의 프로토콜에 대한 메시지와 프리미티브를 정의하여, 이 를 토대로 OBP 탑재 위성 B-ISDN 중계망 연동을 위한 기본 호 처리 절차를 설계 및 검증 하고, 이를 구현하였다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.5
• /
• pp.925-933
• /
• 2003

Network is expected to be developed into optical Internet network collected IP layer and optical layer, but GMPLS is risen at the transitional evolution stage because of the present technology level. GMPLS that MPLS is extended and generalized is able to support not only the packet switching device but also the devices which perform switching in time, wavelength, and space domain. To implement the common control plane to these various switching types, GMPLS extends the existing MPLS signaling and routing protocol. In this paper, we describe the overview of GMPLS technology, and then we will refer to the OSPF(Open Shortest Path First), which was used to exchange the status information of link, as the plan of routing extension to exchange the information of various link type, bandwidth, link protection type etc. And also, we describe the definition of new protocol, so called, LMP that is a signaling protocol for solving complex problem which manages hundreds and thousands of links between two nodes. And we will examine and analyze the plan of signaling protocol extension to apply signaling protocol RSVP-TE(Resource Reservation Protocol) for traffic engineering in MPLS to network, and the message objects and formats associated with modified RSVP.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.1541-1550
• /
• 2007

A subway is one of many public transportation means that contributes toward our society including seoul and offering of its service and expression of various information are in need due to users high demand. And there are various class of users. For that reason an optical communication network in the general contorl center and station buildings was installed. Considering the importance of safe operation of subway, optical communication exists to enhance customer satisfaction. Safe operation is essential as its level of reliance accounts for about 95%. this paper will look for ways to promote mutual information interchange and operation know-how with systems of the same kind and sharing a capable of effective operation of systems in place. Optical communication network in the metropolis railroad accepts various kinds of control networks and data networks for train operation. As occasion demands, this paper presents effective application scheme and specialized organization about an optical communication operating system.

• Journal of Navigation and Port Research
• /
• v.33 no.10
• /
• pp.685-690
• /
• 2009

International Maritime Organization (IMO) recommends the installation of an Automatic Identification System (AIS) according to requirements by SOLAS to avoid maritime collision. AIS provides traffic information of other ships that may be used for maritime traffic control, SAR (Search and Rescue) and collision avoidance to apply safety management. In this paper, preliminary results to implement an aeronautical surveillance transceiver using AIS transceiver based on ADS-B concepts are described. Although altitude information is not required for AIS since the AIS is operated at MSL (Mean Sea Level), altitude information can be extracted by a GPS (Global Positioning System) chip-set in the AIS transceiver. ADS-B transceiver is implemented by defining a surveillance message format including the altitude information and modifying SOTDMA (Self-Organizing Time Division Multiple Access) protocol. Ground tests and flight tests are performed to validate the implementation results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.10a
• /
• pp.87-90
• /
• 2007

Many moderncommunication technologies are developing based on internet protocol (IP) and there is many work to archive seamless mobility service. IETF proposed MIPv6 protocol that uses IPv6 to provide mobility services to mobile node however it has some limits like sending and receiving too many messages during binding update (BU) procedure. So, now a day it makes HMIPv6(Hierarchical Mobile IPv6). HMIPv6 solves overhead and transmission delay problem in MAP(Mobile Anchor Pointer), but it can't accomplish effectively Macro handover between MAPs. This paper introduces use of FMIPv6 and Selective handover mechanisms based on hierarchical MAP information in HMIPv6 for improvement of handover efficiency.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.856-858
• /
• 2013

The data which is sensed on USN(Ubiquitous Sensor Network) environment is concerned with personal privacy and the secret information of business, but it has more vulnerable characteristics, in contrast to common networks. In other words, USN has the vulnerabilities which is easily exposed to the attacks such as the eavesdropping of sensor information, the distribution of abnormal packets, the reuse of message, an forgery attack, and denial of service attacks. Therefore, the key is necessarily required for secure communication between sensor nodes. This paper proposes a KDPC(Key Distribution Protocol based on Cluster) using ECDH algorithm by considering the characteristics of sensor network. As a result, the KDPC can provide the safe USN environment by detecting the forgery data and preventing the exposure of sensing data.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.8
• /
• pp.2171-2178
• /
• 1999

In these days, as rapid growth of multimedia industries and development of techniques, and effort to develop DAVIC(Digital Audio-Visual Council) systems which support multimedia services such as VOD(Video onn Demand) and teleshopping is being done. Therefore it will be indispendable to establish a new conformance testing method related DAVIC system with respect to their standard specification. DSM-CC is a core part of DAVIC and adopts DSM-CC U-N for S3 information stream which plays a part in connection establishment and release of session and transmission layer, and DSM-CC U-U for S2 which operates user application of the system. In this paper, we propose a new conformance testing architecture and methodology based on scenario in order to test DSM-CC U-U which doesn't have any message sequences.