• Title/Summary/Keyword: 관리 프로토콜

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Design of an Leader Election Protocol in Mobile Ad Hoc Distributed Systems (분산 이동 시스템에서 선출 프로토콜의 설계)

  • Park, Sung-Hoon
    • The Journal of the Korea Contents Association
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    • v.8 no.12
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    • pp.53-62
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    • 2008
  • The Election paradigm can be used as a building block in many practical problems such as group communication, atomic commit and replicated data management where a protocol coordinator might be useful. The problem has been widely studied in the research community since one reason for this wide interest is that many distributed protocols need an election protocol. However, despite its usefulness, to our knowledge there is no work that has been devoted to this problem in a mobile ad hoc computing environment. Mobile ad hoc systems are more prone to failures than conventional distributed systems. Solving election in such an environment requires from a set of mobile nodes to choose a unique node as a leader based on its priority despite failures or disconnections of mobile nodes. In this paper, we describe a solution to the election problem from mobile ad hoc computing systems. This solution is based on the Group Membership Detection algorithm.

Dynamic Copy Security Protocol In Real-Time Database Systems (실시간 데이터베이스 시스템에서의 동적 복사 보안 프로토콜)

  • Park, Su-Yeon;Lee, Seung-Ryong;Jeong, Byeong-Su;Seung, Hyeon-U
    • Journal of KIISE:Software and Applications
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    • v.26 no.8
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    • pp.955-963
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    • 1999
  • 다단계 보안 실시간 데이타베이스 시스템은 데이타베이스의 일관성 유지와 실시간 요구인 마감시간의 만족, 그리고 기밀성을 띤 데이타가 노출될 수 있는 비밀채널(covert-channel)의 방지라는 요구사항을 모두 만족해야 한다. 기존의 SRT-2PL(Secure Real-Time 2 Phase Locking)은 원본과 복사본으로 데이타 객체를 분리시켜 다른 등급간에 불간섭(non-interference)을 유지하여 비밀채널의 방지를 가능하게 하였으나, 복사본이 모든 데이타 객체에 대해 항상 존재하므로 메모리의 낭비가 있을 수 있고, 복사본의 갱신을 위한 갱신 큐의 관리에 따르는 오버헤드와 그에 따른 예측성 결여라는 문제점을 갖고 있다. 이를 개선하기 위하여 본 논문에서는 다단계 보안 실시간 데이타베이스 시스템의 요구사항을 모두 만족하는 동적 복사 프로토콜을 제안한다. 동적 복사 프로토콜은 로킹 기법을 기초로 동작하고, 트랜잭션의 작업에 따라 동적으로 복사본을 생성하고 삭제한다. 모의 실험 결과 제안한 동적 복사 프로토콜은 비밀채널을 방지하고 동적인 복사본의 생성으로 SRT-2PL의 단점인 메모리 낭비를 줄일 수 있으며, 예측성을 높여 마감시간 오류율을 감소시켰다.Abstract Concurrency control of real-time secure database system must satisfy not only logical data consistency but also timing constraints and security requirements associated with transactions. These conflicting natures between timing constraints and security requirements are often resolved by maintaining several versions(or secondary copies) on the same data items. In this paper, we propose a new lock-based concurrency control protocol, Dynamic Copy Security Protocol, ensuring both two conflicting requirements. Our protocol aims for reducing the storage overhead of maintaining secondary copies and minimizing the processing overhead of update history. Main idea of our protocol is to keep a secondary copy only when it is needed to resolve the conflicting read/write operations in real time secure database systems. For doing this, a secondary copy is dynamically created and removed during a transaction's read/write operations according to our protocol. We have also examined the performance characteristics of our protocol through simulation under different workloads while comparing the existing real time security protocol. The results show that our protocol consumed less storage and decreased the missing deadline transactions.

A Study on the Call-Setup and Message Mapping for Interworking between H.323 and SIP (H.323과 SIP간의 상호 연동을 위한 호 설정과 메시지 매핑에 관한 연구)

  • Kim, Jeong-Seok;Tae, Won-Kwi;Kim, Jeong-Ho;Ban, Jin-Yang
    • Journal of the Korea Computer Industry Society
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    • v.5 no.9
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    • pp.1017-1024
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    • 2004
  • In this paper, we propose the progressed interworking method between H.323 and SlP, then explain the improved property. The VolP(Voice over Internet Protocol) technology which is able to use a voice service through internet is more cheaper then existing telephone charges, and is easil)· accept the various of multimedia services from internet. Previous connectionmethod of VoIP used H.323 protocol, but it is very complex to connection establishment. so, the SIP(Session Initiation Protocol) protocol that propose in SIP-Working Group is in use recently. Therefore, we need new interworking methodology between H.323 and SIP Products. In this thesis, the progress interworking method between H.323 and SIP are Propose, then interpret unnecessary packet delay for call setup and improved feature of message exchange.

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A Buffer Size-based Retransmission Persistence Control for ARQ Protocols (버퍼 크기 기반 자동재전송 프로토콜의 재전송 지속성 제어)

  • Kim, Beom-Joon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.6 no.4
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    • pp.487-492
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    • 2011
  • This paper proposes a retransmission persistence control scheme for automatic retransmit request (ARQ) protocol to improve the reliability of a wireless link. Most existing ARQ protocols adopt a fixed retransmission persistence. If the ARQ protocol sets the retransmission persistence too low, there is a limitation in providing transmission reliability. On the other hand, if the ARQ protocol sets the retransmission persistence too high, it increases transmission delay and jitter. In order to figure out the problem, the proposed scheme considers the number of frames in the buffer in controlling the retransmission persistence; it improves the throughput of ARQ protocol by increasing the retransmission persistence when the number of frames is small and decreasing otherwise. Simulation results show that the proposed scheme decreases the transmission delay and jitter significantly comparing to the existing schemes.

Backhaul Resource Allocation Protocol for Underwater Cellular Communication Networks (수중 셀룰러 통신 네트워크에서 백홀 자원분배 프로토콜에 관한 연구)

  • Yun, Changho;Park, Jong-Won;Choi, Suhan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.42 no.2
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    • pp.393-402
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    • 2017
  • Just like terrestrial cellular networks, underwater cellular communication networks, which can manage the overall network resource by adaptively allocating backhaul resource for each base station according to its ingress traffic, are necessary. In this paper, a new resource allocation protocol is proposed for the underwater cellular communication network, allocating backhaul resource of a base station proportional to its ingress traffic to the base station. This protocol is classified into two types dependent upon allocation period: the resource allocation protocol with adaptive period and that with fixed period. In order to determine a proper resource allocation protocol, the performance of the two protocols, in terms of reception rate, message overhead, and latency is compared and investigated via simulation. As a result, the resource protocol with adaptive period outperforms that with fixed period; the resource allocation protocol with fixed period results in a maximum of $10^2$ order longer queueing delay as well as $10^2$ order greater message overhead than that with adaptive period.

Cryptanalysis and Remedy Scheme on Qiu et al.'s Enhanced Password Authentication Scheme for SIP (SIP를 위한 Qiu등의 개선된 패스워드 인증 기법에 대한 보안 분석 및 강화 기법)

  • Kim, Hyunsung
    • Journal of Digital Convergence
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    • v.18 no.5
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    • pp.249-256
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    • 2020
  • The session initiation protocol (SIP) is a signaling protocol, which is used to controlling communication session creation, manage and finish over Internet protocol. Based on it, we can implement various services like voice based electronic commerce or instant messaging. Recently, Qiu et al. proposed an enhanced password authentication scheme for SIP. However, this paper withdraws that Qiu et al.'s scheme is weak against the off-line password guessing attack and has denial of service problem. Addition to this, we propose an improved password authentication scheme as a remedy scheme of Qiu et al.'s scheme. For this, the proposed scheme does not use server's verifier and is based on elliptic curve cryptography. Security validation is provided based on a formal validation tool ProVerif. Security analysis shows that the improved authentication scheme is strong against various attacks over SIP.

A Design of Secure Mobile Agent Systems Employing ID based Digital Multi-Signature Scheme (ID기반 디지털 다중 서명 기술을 적용한 안전한 이동 에이전트 시스템의 설계)

  • Yoo, Seong-Jin;Kim, Seong-Yeol;Lee, Ok-Bin;Chung, Il-Yong
    • The KIPS Transactions:PartC
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    • v.10C no.1
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    • pp.17-26
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    • 2003
  • Mobile agent system comes into the spotlight since it contributes largely to mobile computing on distributed network environment. However, this system has a number of significant security Problems. In this Paper, we analyze suity attacks to mobile agent system Presented by NIST[3]. In order to protect this system from them, we suggest a security protocol for mobile agent system by employing R based key distribution and digital multi-signature scheme. To solve these problems described in NIST, securities for mobile agent and agent platform shouid be accomplished. Comparing with other protocols, our protocol performs both of these securities, while other protocols mentioned only one of them. Proposed Protocol satisfies simplicity of key management, providing security service such as confidentiality, integrity, authentication and preventing reputation, liveness guarantee, protection of excution-result data and preventing replay attack. Furthermore, it is designed to detect message modification immediately by verifying each step of agent execution at a corresponding server.

Design and Implementation of Customized Protocol and Smartphone App for the All-in-One Sensor Device

  • Bang, Jong-ho;Lee, Song-Yeon;Paik, Jong-Ho
    • Journal of Internet Computing and Services
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    • v.19 no.1
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    • pp.19-26
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    • 2018
  • Social issues for environmental pollution are continuously increasing globally. Especially, Users require services to measure environmental factors in indoor and outdoor and manage related data effectively and conveniently. According to this demand, sensors that can measure environmental factors in indoor and outdoor have been developed. However, since one sensor is composed of independent module, the interface of output data from each sensor is different. To solve the problem, we propose a customized protocol for low-power short-range wireless communication between smartphone using Bluetooth and All-in-One sensor device board and analyze the performance of the proposed customized protocol by developing program for performance verification of interface with user smartphone through Bluetooth. In addition, we implement a smartphone application using proposed protocol.

A Design and Implementation of Device Driver Architecture of IEEE 1394 Network Adaptor for Guaranteeing Real-Time Characteristics (IEEE 1394 네트웍에서 실시간성 보장을 위한 디바이스 드라이버 소프트웨어 구조 설계 및 구현)

  • 박동환;임효상;강순주
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.4C
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    • pp.295-307
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    • 2002
  • The IEEE 1394 protocol is a de facto standard in multimedia digital home network. It supports several advanced features such as hot plugging, dynamic network reconfiguration, isochronous transmission and so on. Since the IEEE 1394 was adapted in the field of multimedia service with QoS guarantee, back bone network protocol with reel-time digital instrumentation and control sub networks, and physical layer protocol for real-time middleware such as real-time CORBA, the additional real-time features has been required in device driver implementation because of the necessity of the predictability enhancement. To guarantee the real-time features, the device driver of the IEEE 1394 should support the priority based packet processing and also need a isochronous buffer management mechanism to deal with the periodic isochronous communication. In this paper, we proposed a new software architecture of the IEEE 1394 device driver for supporting the real-time characteristics such as priority based packet processing, priority based scheduling and so on.

MA(Mesh Adaptive)-CBRP Algorithm for Wireless Mesh Network (Wireless Mesh Network를 위한 MA(Mesh Adaptive)-CBRP 알고리즘의 제안)

  • Kim, Sung-Joon;Cho, Gyu-Seob
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.11B
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    • pp.1607-1617
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    • 2010
  • In this paper we propose MA-CBRP, mesh adaptive algorithm for wireless mesh networks. MA-CBRP is a hybrid algorithm based on ad-hoc CBRP protocol. In MA-CBRP, the mesh router periodically sends the ANN message as like Hello-message in CBRP. ANN message allows to all clients periodically store a route towards the mesh-router and renewal information in their routing cache. While CBRP periodically reply Hello-message, MA-CBRP does not reply to achieve less overhead. After receiving ANN message, mesh client send JOIN message to mesh router when the route towards mesh router changed. at the same time Register the entry to mesh router, it can achieve to reduce overhead of control the route and shorten the time to find route. consequently, MA-CBRP shows 7% reduced overhead and shortened time to find route than CBRP with regardless of clients number.