• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.4
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• pp.1032-1040
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• 2010

This paper describes implementation of electonic seal (E-Seal) of a container based on ISO 18185 standard and development of monitoring systems checking E-Seal device and cargo states in the container for secure transportation from departure to destination. For lack of definition on confidentiality support in ISO 18185-4 standard, it is vulnerable to security attack such as sniffing. To cope with this, we developed encryption/decryption functions implementing RC5 and AES-128 standards and compared their performance. Experimental results showed that RC5 outperformed AES-128 in terms of time delay. In addition, RC5 had an advantage under the condition of large sized messages as well as CPUs with low performance. However, the portion of encryption/decryption processing time was less than 1 percent of response time including communication delay between E-Seal tags and readers. Hence, the performance difference between RC5 and AES-128 standards was trivial, which revealed that both specifications were allowable in developed systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7C
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• pp.696-705
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• 2005

The rapid progress of the software has enabled individuals to copy and remake digital contents, which was only done by professionals. However, this rapid growth of software has brought many other defects. As a solution to the problems, contents producer needs to have certification and inspection of its contents text and hold the proprietary rights. In this paper, the new video watermarking scheme is proposed which is appropriate for the requirements mentioned for digital video contents and it is applied to MPEG-2 video encoder and decoder. In order to insert watermark sequence for digital video data, watermarking used blocks reordering algorithm and SCL(secret code list). It is satisfied two properties of cryptography that confidentiality and integrity. We test the proposed algorithm to see its performance in terms of watermark capacity, compression robustness and visual quality impact. According to the experiment of proposed watermarking algorithm, we obtained satisfactory results that watermark can still be extracted after MPEG-2 re-encoding at lower bit rates. It is important property for data hiding and user authentication in video data.

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.831-840
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• 2002

Due to the advance of computer and communication technology, intrusions or crimes using a computer have been increased rapidly while tremendous information has been provided to users conveniently Specially, for the security of a database which stores important information such as the private information of a customer or the secret information of a company, several basic suity methods of a database management system itself or conventional misuse detection methods have been used. However, a problem caused by abusing the authority of an internal user such as the drain of secret information is more serious than the breakdown of a system by an external intruder. Therefore, in order to maintain the sorority of a database effectively, an anomaly defection technique is necessary. This paper proposes a method that generates the normal behavior profile of a user from the database log of the user based on an association mining method. For this purpose, the Information of a database log is structured by a semantically organized pattern tree. Consequently, an online transaction of a user is compared with the profile of the user, so that any anomaly can be effectively detected.

• Journal of KIISE
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• v.42 no.8
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• pp.1049-1056
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• 2015

Runtime Intrusion Prevention Evaluator (RIPE), published in 2011, is a benchmark suite for evaluating mitigation techniques against 850 attack patterns using only buffer overflow. Since RIPE is built as a single process, defense and attack routines cannot help sharing process states and address space layouts when RIPE is tested. As a result, attack routines can access the memory space for defense routines without restriction. We separate RIPE into two independent processes of defense and attacks so that mitigations based on confidentiality such as address space layout randomization are properly evaluated. In addition, we add an execution mode to test robustness against brute force attacks. Finally, we extend RIPE by adding 38 attack forms to perform format string attacks and virtual table (vtable) hijacking attacks. The revised RIPE contributes to the diversification of attack patterns and precise evaluation of the effectiveness of mitigations.

• Fire Science and Engineering
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• v.23 no.6
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• pp.91-97
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• 2009

The mass flow rates and performance of natural smoke ventilators in high-rise buildings with 40, 80, 120 stories were evaluated using CONTAMW tool. The results showed that only limited part of smoke ventilators can have positive exhaust flow in high-rise buildings due to stack effect and wind velocities. In the higher story buildings larger stack effect can overcome outside strong wind effect to give more ventilation performance. The air tightness of the building have strong effect on the exhaust performance of the ventilators to give lower performance with loose air tightness of the exterior walls.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.3
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• pp.220-228
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• 2001

Digital watermarking is a technique for the purpose of protecting the ownership of the image by embedding invisible watermarks in a digital imnge. To guarantee the security of the digital watermarking scheme for copyright protection, it is required to satisfy some requirements robustness and perceptual invisibility which provided by the location of embedded bits, the public watermarking algorithm, and the hidden use of the key, which can protect unauthorized accesses from illegal users. For this, in this paper we propose a new copyright watermarking scheme, which is based on one-way hash functions using RSA functions and modular operations. RSA functions are widely used in cryptographic systems. Our watermarking scheme is robust against LSB(Jeast significant bit) attacks and gamma corresction attack, and is also perceptually invisible. We demonstrate the characteristics of our proposed watermarking scheme through experiments.

• Journal of Internet Computing and Services
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• v.9 no.6
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• pp.1-13
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• 2008

Trusted Computing is a hardware-based technology that aims to guarantee security for machines beyond their users' control by providing security on computing hardware and software. TPM(Trusted Platform Module), the trusted platform specified by the Trusted Computing Group, acts as the roots for the trusted data storage and the trusted reporting of platform configuration. Data sealing encrypts secret data with a key and the platform's configuration at the time of encryption. In contrast to the traditional data sealing based on binary hash values of the platform configuration, a new approach called property-based data sealing was recently suggested. In this paper, we propose and analyze a new property-based data sealing protocol using the weakest precondition concept by Dijkstra. The proposed protocol resolves the problem of system updates by allowing sealed data to be unsealed at any configuration providing the required property. It assumes practically implementable trusted third parties only and protects platform's privacy when communicating. We demonstrate the proposed protocol's operability with any TPM chip by implementing and running the protocol on a software TPM emulator by Strasser. The proposed scheme can be deployed in PDAs and smart phones over wireless mobile networks as well as desktop PCs.

• Journal of KIISE
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• v.44 no.10
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• pp.1112-1123
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• 2017

As content providers further offload content-centric services to the cloud, data retrieval over the cloud typically results in many redundant items because there is a prevalent near-duplication of content on the Internet. Simply fetching all data from the cloud severely degrades efficiency in terms of resource utilization and bandwidth, and data can be encrypted by multiple content providers under different keys to preserve privacy. Thus, locating near-duplicate data in a privacy-preserving way is highly dependent on the ability to deduplicate redundant search results and returns best matches without decrypting data. To this end, we propose an efficient near-duplicate detection scheme for encrypted data in the cloud. Our scheme has the following benefits. First, a single query is enough to locate near-duplicate data even if they are encrypted under different keys of multiple content providers. Second, storage, computation and communication costs are alleviated compared to existing schemes, while achieving the same level of search accuracy. Third, scalability is significantly improved as a result of a novel and efficient two-round detection to locate near-duplicate candidates over large quantities of data in the cloud. An experimental analysis with real-world data demonstrates the applicability of the proposed scheme to a practical cloud system. Last, the proposed scheme is an average of 70.6% faster than an existing scheme.

• Composites Research
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• v.35 no.3
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• pp.147-152
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• 2022

Low-temperature characteristics according to internal temperature conditions during rotational molding of Type 4 pressure vessel liners were studied in this paper. Since rotational molding has a sensitive effect on the formability of the liner depending on the temperature conditions, the temperature conditions for the polyamide used should be accurately set. The structural changes of polyamide as the liner material was analyzed the surface by atomic force microscope (AFM), and the crystallinity measured with a differential scanning calorimeter (DSC) is used to evaluate the change of the mechanical strength value at low temperature. In addition, the formability of the liner was confirmed by observation of the yellow index inside the liner. As a result, as the melting range of the internal temperature becomes wider, the yellow index shows a lower value, and the elongation and impact characteristics at low temperatures are improved. It was also confirmed that the structure of the polyamide was uniform and the crystallinity was high by AFM and DSC. These experimental results contribute to the improvement of characteristics at low temperatures due to changes in temperature conditions during rotational molding.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.249-249
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• 2013

지식경제부의 청정제조기반 산업원천개발사업의 일환으로 진행 중인 "초고진공펌프 개발" 과제 중 제 3 세부 과제인 "고진공펌프종합특성평가시스템 설계, 진단기술 개발" 과제에서 진행되고 있는 연구수행결과 및 기 구축 돈 저진공펌프 종합특성평가시스템을 활용한 진공펌프의 상용화를 위한 신뢰성 평가에 관하여 소개한다. 10(3) mbar~ 10(-10) mbar 영역의 국내 진공펌프 개발 수준의 선진화를 위한 모든 특성평가장치의 국제적 신뢰성이 있는 완벽한 성능평가의 구현에 있다고 할 수 있다. 고진공펌프개발 총괄과제의 대명제는 "국제적 신뢰성을 가지는 상용화 제품의 완성"이며, 전체 사업 추진기간 동안 제품 개발 주체인 산업체에 상용화를 위한 신뢰성 기반기술의 완벽한 구현의 제공에 있다고 할 수 있다. 이러한 고진공펌프의 신뢰성 평가는 저진공펌프의신뢰성 평가기술에 기반을 두고 있으며, 기 개발 완료된 특성평가뿐만 아니라 실질적으로 공정현장에서 판단할 수 있는 내구성진단 및 제작회사에서의 기계적 신뢰성 진단기술의 복합적인 요인들의 집합적인 분석에 기인하고 있다고 판단할 수 있다. 상용화 단계의 내구성 및 신뢰성 확보를 위한 전제 조건은 대외적으로 공표할 수 있는 시험평가 데이터와 개발 주체에서 기밀 수준으로 유지해야만 하는 민감한 자료의 상시 생산 infra의 구축으로 볼 수 있다. 이러한 진공펌프개발이라는 과제의 대명제를 완성하기 위하여 추진 연구개발 방향 등 진행형인 2년간의 최종 상용화에 필요한 국제 신뢰성, 공정대응성 확보 등 핵심사업 추진내용을 소개하고자 한다.