• Journal of KIISE:Information Networking
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• v.33 no.1
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• pp.1-8
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• 2006

Security protocols have usually been developed using informal design and verification techniques. However, many security protocols thought to be secure was found to be vulnerable later. Thus, the importance of formal specification and verification for analyzing the safely of protocols is increasing. With the rise of mobile communication networks, various mobile security protocols have been proposed. In this paper, we identify the security weakness of the ASK mobile Protocol using formal verification technique. In addition, we propose a new ASK protocol modifying its vulnerability and verify its robustness.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1452-1455
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• 2004

In this paper, we develope a protocol verification tool that verifies the correctness of rail signal control protocol type 2 specified in LTS(Labeled Transition System) by using model checking method. This tool automatically checks several properties for deadlock, livelock and reachability of states and actions on LTS. and removes many errors and ambiguities of an informal method used in the past, so saves down expenditures and times required in the protocol development. Therefore it is expected that there will be an increase in safety, reliability and efficiency in terms of the maintenance of the signaling system by using the developed verification tool.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.5
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• pp.650-662
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• 1993

The thesis describes the realization and test of the transport layer operating on the CLNS (Connection Less Network Service) which is specified by ISO 8073 and ADDENDUM 2 protocol. For realization of the transport layer, five modules and interface primitives were definde. This protocol was formally described by SDL (Specification and Description Language) and was programmed in C-language. For verification of the software, protocol tester was implemented and test scenarios were defined. The verification was accomplished based on the test scenarios. Transport Layer software presented in this thesis may be utilized in a real situation with some modifications. Protocol tester presented in this thesis can also be used for verification of other protocol softwares.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.581-586
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• 2003

As a very important part in development of the protocol, verification and conformance test for protocol specification are complementary techniques that are used to increase the level of confidence in the system functions. as prescribed by their specifications. In this paper, we verify the safety and liveness properties of rail signal control protocol type 1 specified in LTS(Labeled Transition System) with model checking method, and experimentally prove that it is possible to check for the deadlock, livelock and rechability of the states and actions on LTS. We also propose a formal method on generation of conformance test cases using the concept of UIO sequences from verified protocol specification.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.719-722
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• 2000

It is essential to develop the internetworking strategies between the OBP satellite B-ISDN and the terrestrial B-ISDN for the economical and efficient implementation of the future network infrastructure. We have considered the implementation issues of the emerging B-ISDN, especially interworking strategies of the terrestrial B-ISDN with the OBP satellite B-ISBN. We proposed interworking model between terrestrial B-ISDN and OBP satellite B-ISDN NNI signaling protocol, and describes the design and verification of the interworking protocol. For the verification, interworking protocol is modeled by Predicate/Action Net derived from Petri Net and the designed model is analyzed by reachability tree. Using Unix socket, the verified interworking protocol is implemented in two workstations and implemented interworking protocol is tested by local test method which is outstanding in error detection and recommended by ISO.

• Journal of Korea Multimedia Society
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• v.15 no.8
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• pp.1048-1058
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• 2012

This paper proposes the DDMPF(Distributed Data Management Protocol using FAT) which prevents data loss and keeps the security of self-organized storages by comprising a client, a storage server, and a verification server in clouding environment. The DDMPF builds a self-organized storage server, solves data loss by decentralizing the partitioned data in it in contrast to the centralized problem and the data loss caused by the storage server problems of existing clouding storages, and improves the efficiency of distributed data management with FAT(File Allocation Table). And, the DDMPF improves the reliability of data by a verification server's verifying the data integrity of a storage server, and strengthens the security in double encryption with a client's private key and the system's master key using EC-DH algorithm. Additionally, the DDMPF limits the number of verification servers and detects the flooding attack by setting the TS(Time Stamp) for a verification request message and the replay attack by using the nonce value generated newly, whenever the verification is requested.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.7
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• pp.332-339
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• 2008

Radio Frequency Identification (RFID) technology is an important part of infrastructures in ubiquitous computing. Although all products using tags is a target of these services, these products also are a target of attacking on user privacy and services using authentication problem between user and merchant, unfortunately. Presently, it is very important about security mechanism of RFID system and in this paper, we analyze the security protocol among many kinds of mechanisms to solve privacy and authentication problem using formal verification and propose a modified novel protocol. In addition, the possibility of practical implementation for proposed protocol will be discussed.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.6
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• pp.380-387
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• 2004

In accordance with the computerization of railway signaling systems, the interface link between the signaling systems has been replaced by a digital communication channel. At the same time, the importance of the communication link has become increasingly significant. However, there are some questionable matters in the current state of railway signaling systems in KNR. First, different communication protocols have been applied to create an interface between railway signaling systems although the protocols have the same functions. Next, the communication protocols currently used in the railway fields have some illogical parts such as structure, byte formation, error correction scheme, and so on. To solve these matters, the standard communication protocol for railway signaling systems is designed. The newly designed protocol is overviews in this paper. And the simulation is performed to analysis the performance of data link control for designed protocol. According to this simulation, it is identified that the link throughput of new protocol is improved about 10% and the frame error rate is improved than existing protocol. And it is verified the safety and liveness properties of designed protocol by using a formal method for specifying the designed protocol. It is expected that there will be an increase in safety, reliability and efficiency in terms of the maintenance of the signaling systems by using the designed communication protocol for railway signaling.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.111-118
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• 2013

The connection based TCP protocol provides reliable packet delivery, but it takes certain overhead compare to the connection-less UDP protocol. Thus, 3GPP devise the upper-layer RLC protocol which provides reliability based upon the UDP protocol. Consequently, each implement of a base station and/or mobile terminal require the development of the RLC protocol, and it must qualify various interoperable tests. In this paper, we implement a testbed which verifies the RLC protocol under various packet losses/inversion circumstances of networks. Finally, we propose our testbed as the RLC protocol tester for the developments.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.354-357
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• 2004

According to the computerization of railway signaling systems, the interface link between the signaling systems has been replaced by the digital communication channel. At the same time, the importance of the communication link is more pronounced than in the past. In this paper, new network-based protocol for Korean railway signaling has designed between CTC and SCADA system, and the overview of designed protocol is briefly represented. Using the informal method for specifying the communication protocol, a little ambiguity may be contained in the protocol. To clear the ambiguity contained in the designed protocol, we use LTS model to design the protocol for this interface link between CTC and SCADA, the LTS is an intermediate model for encoding the operational behavior of processes. And then, we verify automatically and formally the safety and the liveness properties through the model checking method. Especially, the modal ${\mu}$-calculus, which is a highly expressive method of temporal logic that has been applied to the model checking method. It will be expected to increase the safety, reliability and efficiency of maintenance of the signaling systems by using the designed protocol for railway signaling in Korea.