• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.251-260
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• 2011

In this paper, we proposed a scheme that it safely exchanges encrypted keys without Trust Third Party (TTP) and Pre-distributing keys in multi-hop clustering sensor networks. Existing research assume that it exists a TTP or already it was pre-distributed a encrypted key between nodes. However, existing methods are not sufficient for USN environment without infrastructure. Some existing studies using a random number Diffie-Hellman algorithm to solve the problem. but the method was vulnerable to Replay and Man-in-the-middle attack from the malicious nodes. Therefore, authentication problem between nodes is solved by adding a ��TESLA. In this paper, we propose a modified Diffie-Hellman algorithm that it is safe, lightweight, and robust pair-wise agreement algorithm by adding One Time Password (OTP) with timestamp. Lastly, authentication, confidentiality, integrity, non-impersonation, backward secrecy, and forward secrecy to verify that it is safe.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.1
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• pp.35-45
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• 2004

In explosively increasing internet environments, information security is one of the most important consideration. Nowadays, various security solutions are used as such problems countermeasure; IDS, Firewall and VPN. However, basically internet has much vulnerability of protocol itself. Specially, it is possible to establish a covert channel using TCP/IP header fields such as identification, sequence number, acknowledge number, timestamp and so on. In this Paper, we focus cm the covert channels using identification field of IP header and the sequence number field of TCP header. To detect such covert channels, we used Support Vector Machine which has excellent performance in pattern classification problems. Our experiments showed that proposed method could discern the abnormal cases(including covert channels) from normal TCP/IP traffic using Support Vector Machine.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.4
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• pp.719-731
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• 2012

One of the most important point in the Internet crime investigation is tracing back and pointing out a criminal host. However, criminals can forge a crime record stored in the crime host, or can utilize malicious applications in order not to leave a crime record. In addition, criminals can change the source IP address of a crime host and deny their involvement. In this study, we suggests the Network Forensic Evidence Generation and Verification Scheme (NFEGVS) to rectify the current limitation of Network Forensic technologies. This scheme can prove who and when the crime has occurred. In addition, this prevents leaking of symmetric key for guaranteeing certification and integrity of Forensic Evidence by proposing the Timestamp Secret Key Distribution Scheme, and minimizes performance degradation of router when generating forensic evidence with the Flow-Based Selection Scheme. In this paper, we implement the proposed scheme and evaluate overall performance of the proposed system.

• Journal of Korea Society of Industrial Information Systems
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• v.29 no.1
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• pp.107-116
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• 2024

Copper Filter Dryer (CFD) are responsible for removing impurities from the circulation of refrigerant in refrigeration and cooling systems to maintain clean refrigerant, and defects in CFD can lead to product defects such as leakage and reduced lifespan in refrigeration and cooling systems, making quality assurance essential. In the quality inspection stage, human inspection and defect judgment methods are traditionally used, but these methods are subjective and inaccurate. In this paper, YOLOv7 object detection algorithm was used to detect defects occurring during the CFD Shaft pipe and welding process to replace the existing quality inspection, and the detection performance of F1-Score 0.954 and 0.895 was confirmed. In addition, the cause of defects occurring during the welding process was analyzed by analyzing the sensor data corresponding to the Timestamp of the defect image. This paper proposes a method for manufacturing quality assurance and improvement by detecting defects that occur during CFD process and analyzing their causes.

• Journal of information and communication convergence engineering
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• v.5 no.2
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• pp.159-163
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• 2007

RFID applications are mostly associated with the timestamp when the events occur. For managing RFID data we need to design data modeling for RFID data to support monitoring and temporal queries. In this paper, we propose a temporal RFID data modeling to maintain the history of events and state changes and to monitor the states of RFID objects. This data modeling involves essential basic operations for RFID data to monitor the information of RFID objects and to support temporal queries. Filter operations can achieve better query performance and obtain efficient storage space usage. It is possible to adapt into different temporal business applications.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.13-15
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• 2004

최근에 공간 정보들의 이력 정보를 효과적으로 다를 수 있는 기술에 대한 연구가 활발하게 이루어지고 있다. 이러한 기술은 토지 관리 시스템이나 시간에 따라 변하는 지리 정보들을 처리하는 시스템에서 유용하게 사용되어질 수 있다. 본 논문에서는 시간의 흐름에 따라 변화하는 공간정보 질의들의 최적화를 위한 선택도 추정 기법을 제시한다. 기본 개념은 Minskew 히스토그램을 이용하여 공간 히스토그램을 구축하고, 이를 timestamp에 따라 재구축 한 뒤 유지하는데 기반하고 있다. 또한, 정확한 선택도 추정률을 유지하고 히스토그램 재구축 횟수를 줄이기 위해 히스토그램 변경 내용이 최적의 임계치를 넘어 섰을 때만 시공간 데이터베이스에 현존하는 엔트리를 기반으로 히스토그램을 새로 구축하는 기법을 제시한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1147-1150
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• 2006

Stream Control Transmission Protocol (SCTP) uses the 32-bit checksum in the common header, by which a corrupted SCTP packet will be regarded as a lost packet and then discarded. This may result in degradation of SCTP's throughput performance over wireless networks. This paper proposes a new chunk checksum scheme for SCTP, in which each data chunk contains its own checksum field and SACK chunk carry corresponding Transmission Sequence Number (TSN) with timestamp for every corruption event. The proposed chunk checksum scheme is introduced with the following three purposes: 1) to distinguish the chunk corruptions from the chunk losses; 2) to avoid the unnecessary halving of the congestion window (cwnd) in the case of chunk corruption; 3) to avoid the unwanted timeouts which can be induced in conventional SCTP in the case that the retransmitted data chunks are corrupted again in wireless networks. Simulation results show that the proposed chunk checksum scheme could improve the SCTP throughput in the wireless environments with a high bit error rate.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.2
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• pp.892-905
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• 2018

In smart home environment, certificate based signature technology is being studied by communication with Internet of Things(IoT) device. However, block - chain technology has attracted much attention because of the problems such as single - point error and management overhead of the trust server. Among them, Keyless Signature Infrastructure(KSI) provides integrity by configuring user authentication and global timestamp of distributed server into block chain by using hash-based one-time key. In this paper, we provide confidentiality by applying group key and key management based on multi - solution chain. In addition, we propose a smart home environment that can reduce the storage space by using Extended Merkle Tree and secure and efficient KSI-based authentication and communication with enhanced security strength.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.1
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• pp.9-19
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• 2011

Secure and efficient authentication schemes over insecure networks have been a very important issue with the rapid development of networking technologies. Wang et al. proposed a remote user authentication scheme using smart cards. However, recently, Chen et al. pointed out that their scheme is vulnerable to the impersonation attack and the parallel session attack, and they proposed an enhanced authentication scheme. Chen et al. claimed that their scheme is secure against the various attacks. However, we have found that their scheme cannot resist the parallel attack and the stolen smart card attack. Therefore, in this paper, we show the security flaws in Chen et al.'s scheme and propose an improved remote user authentication scheme using tamper-resistant smart cards to solve the problem of Chen et al.'s scheme. We also analyze our scheme in terms of security and performance.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.318-321
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• 2006

현재 국내 국책사업으로 추진 중인 와이브로(WiBro) 기술 규격이 포함되어 있는 휴대인터넷 표준 규격인 IEEE 802.16e는 IP기반으로, 이동성이 뛰어나고 고속전송 기능의 특징을 가지고 있다. 또한 기지국간의 핸드오버(Handover)를 지원함으로써 이동성을 지원한다. 그러나 이러한 핸드오버 기법에 있어서 Replay 공격, Man-in-the-Middle 공격, Stolen-Verifier 공격 등에 취약한 문제점이 드러나고 있다. 본 논문은 이러한 기존 핸드오버 기법의 취약점을 개선하기 위해서 사용자의 인증서와 Timestamp값을 통한 IEEE 802.16e/와이브로 망에서 안전한 핸드오버 적용 방안에 대해 제안한다.