• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.2
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• pp.811-829
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• 2015

One-way authenticated key agreement protocols, aiming at solving the problems to establish secure communications over public insecure networks, can achieve one-way authentication of communicating entities for giving a specific user strong anonymity and confidentiality of transmitted data. Public Key Infrastructure can design one-way authenticated key agreement protocols, but it will consume a large amount of computation. Because one-way authenticated key agreement protocols mainly concern on authentication and key agreement, we adopt multi-server architecture to realize these goals. About multi-server architecture, which allow the user to register at the registration center (RC) once and can access all the permitted services provided by the eligible servers. The combination of above-mentioned ideas can lead to a high-practical scheme in the universal client/server architecture. Based on these motivations, the paper firstly proposed a new one-way authenticated key agreement scheme based on multi-server architecture. Compared with the related literatures recently, our proposed scheme can not only own high efficiency and unique functionality, but is also robust to various attacks and achieves perfect forward secrecy. Finally, we give the security proof and the efficiency analysis of our proposed scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.1
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• pp.119-131
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• 2013

With the explosive growth of computer networks, many remote service providing servers and multi-server network architecture are provided and it is extremely inconvenient for users to remember numerous different identities and passwords. Therefore, it is important to provide a mechanism for a remote user to use single identity and password to access multi-server network architecture without repetitive registration and various multi-server authentication schemes have been proposed in recent years. Recently, Tsaur et al. proposed an efficient and secure smart card based user authentication and key agreement scheme for multi-server environments. They claimed that their scheme satisfies all of the requirements needed for achieving secure password authentication in multi-server environments and gives the formal proof on the execution of the proposed authenticated key agreement scheme. However, we find that Tsaur et al.'s scheme is still vulnerable to impersonation attack and many logged-in users' attack. We propose an extended scheme that not only removes the aforementioned weaknesses on their scheme but also achieves user anonymity for hiding login user's real identity. Compared with other previous related schemes, our proposed scheme keeps the efficiency and security and is more suitable for the practical applications.

• The KIPS Transactions:PartB
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• v.12B no.4 s.100
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• pp.459-464
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• 2005

The online game system could be largely divided into two parts: servers and clients. Clients accesses to a game server and analyzes the packets transmitted from a server. A game server manages users information and database. U a game server allows a new client to access the server to execute a game, it should accept the access request of the new client maintaining the online connection of the existing users. In this paper, we compare Process method and Thread method within the multiple jobs process methods of a server. Then we propose an asymmetric distributed multi server architecture that is adequate to asymmetric distributed architecture that is widely applied to most game servers. The proposed asymmetric distributed multi server architecture includes login server, game server, communication server and database server to perform its own feature independently. Comparing its other architectures, it shows better performance economically and technically. Especially it improves the stability and expandability of a server.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.7
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• pp.3371-3396
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• 2016

Authentication protocols for multi-server architectures have gained momentum in recent times due to advancements in computing technologies and associated constraints. Lu et al. recently proposed a biometrics and smartcards-based authentication scheme for multi-server environment. The careful analysis of this paper demonstrates Lu et al.'s protocol is susceptible to user impersonation attacks and comprises insufficient data. In addition, this paper proposes an improved authentication with key-agreement protocol for multi-server architecture based on biometrics and smartcards. The formal security of the proposed protocol is verified using the widely accepted AVISPA (Automated Validation of Internet Security Protocols and Applications) tool to ensure that our protocol can withstand active and passive attacks. The formal and informal security analysis, and performance analysis sections determines that our protocol is robust and efficient compared to Lu et al.'s protocol and existing similar protocols.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.3
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• pp.911-931
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• 2021

Recently, most cloud services use Docker container environment to provide their services. However, there are no researches to evaluate the performance of communication libraries for multi-GPU based distributed deep learning in a Docker container environment. In this paper, we propose an efficient communication architecture for multi-GPU based deep learning in a Docker container environment by evaluating the performances of various communication libraries. We compare the performances of the parameter server architecture and the All-reduce architecture, which are typical distributed deep learning architectures. Further, we analyze the performances of two separate multi-GPU resource allocation policies - allocating a single GPU to each Docker container and allocating multiple GPUs to each Docker container. We also experiment with the scalability of collective communication by increasing the number of GPUs from one to four. Through experiments, we compare OpenMPI and MPICH, which are representative open source MPI libraries, and NCCL, which is NVIDIA's collective communication library for the multi-GPU setting. In the parameter server architecture, we show that using CUDA-aware OpenMPI with multi-GPU per Docker container environment reduces communication latency by up to 75%. Also, we show that using NCCL in All-reduce architecture reduces communication latency by up to 93% compared to other libraries.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.10
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• pp.60-71
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• 2012

This paper proposes a new design and implementation of multi-protocol IED for networked control system of multi-induction motor in industrial fields. The experimental multi-induction motor based multi-protocol IED of Modbus/LonTalks/TCP/IP module is designed and fabricated. This article addresses issues in architecture of LonWorks/Ethernet sever, embedded processors architecture for converting Modbus protocol to LonTalks protocol, integrating preconfigured software, and Internet technologies. It is also verified that the multi-induction motor control and monitoring system using LonWorks/Ethernet server have available, interoperable, reliable performance characteristics from the experimental results, especially, the seamless integration of TCP/IP networks with control networks allows access to any control point from anywhere. Thus, the results provide available technical data for remote distributed motor control system of industrial field or building microgrid with LonWorks BAS.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1866-1874
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• 2008

Existing web server lowers the whole capacity of system because of the problem on the processing load of server by closing connection increasing code handshake operation, and remarkable decrease of server capacity if it is the state of overload. Also, there occurs disadvantages of increasing connection tine about client's request and response time because handling of client's multi-requests is not smooth because of thread block and it requests a lot of time and resources for revitalization of thread. Therefore, this paper proposes the extended web server which provides the technique for delay handling and improves the overload of server for better system capacity, communication support, and the unification which is the advantage of web service. And it evaluates the existing system(implemented at Tomcat 5.5) and the proposed mobile web server architecture. The extended server architecture provides excellent exchange condition for system capacity and evaluates improved web server architecture which combines multi-thread with thread pool. The proposed web service architecture in this paper got the better result of improved capacity benefit than the evaluation result of original Tomcat 5.5.

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.340-344
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• 2009

Multi-server password authentication schemes enable remote users to obtain service from multiple servers with single password without separately registering to each server. In 2007, Hu-Niu-Yang proposed an improved efficient password authenticated key agreement scheme for multi-server architecture based on Chang-Lee's scheme proposed in 2004. This scheme is claimed to be more efficient and is able to overcome a few existing deficiencies in Chang-Lee's scheme. However, we find false claim of forward secrecy property and some potential threats such as offline dictionary attack, key-compromise attack, and poor reparability in their scheme. In this paper, we will discuss these issues in depth.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.511-515
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• 2001

Many intelligent agent systems are known to incorporate BDI architecture for cognitive reasoning. Since this architecture contains all the knowledge of world model and reasoning rule, it is very complex and difficult to handle. This paper describes a methodology to design and implement BDI architecture, BDIAXml based on XML for multi-agent systems. This XML-based BDI architecture is smaller than any other BDI architecture because it separates knowledge for reasoning from domain knowledge and enables knowledge sharing using XML technology. Knowledge for BDI mental state and reasoning is composed of specific XML files and these XML files are stored into a specific knowledge server. Most systems using BDIAxml architecture can access knowledge from this server. We apply this BDIAXml system to domain of Hospital Information System and show that this architecture performs more efficiently than other BDI architecture system in terms of knowledge sharing, system size, and ease of use.

• Journal of the military operations research society of Korea
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• v.23 no.2
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• pp.25-44
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• 1997

Internet users been rapidly increased due to the convenient GUI environment. Current Web-based HTTP/CGI client/server architecture has several problems such as the CGI bottleneck, no maintaince of state, and no load balancing. However, with Java and CORBA technologies called“Object Web technology”, we can solve them because Java is not only a mobile code but also a platform-independent code, and CORBA has ability to build distributed object and language-independent object model. The goal of “Object Web technology”is to create multivendor, multiOS, multilanguage“legoware”using objects. This paper implement“Book Search System”which is Web-based client/server architecture using distributed objects. Environments of this implementation are Hangul Windows NT(included IIS) server, Hangul Windows 95 client, Visigenic's VisiBroker for Java 1.2 which is a product of CORBA 2.0, HTTP protocol on TCP-IP-based, Sybase SQL Anywhere 5.0 database server, and the interface between application server and database is JDBC-ODBC bridge middleware.