• 한국콘텐츠학회논문지
• /
• 제7권4호
• /
• pp.20-29
• /
• 2007

전자우편은 인터넷을 이용하는 사용자들에게 중요한 커뮤니케이션의 역할을 담당하고 있다. 하지만, 원하지 않는 광고 정보를 포함한 스팸 메일, 악성코드 형태를 포함한 바이러스 메일 등 대부분이 불필요한 자료들로 인해 전자우편이 가지는 본연의 의미와는 무색하게 사용되고 있어 근본적인 측면에서 스팸 메일의 발송을 방지할 수 있는 방안에 대한 연구가 시급하다. 본 연구에서 전자우편 발송자는 SMS(Short Message Service) 방식으로 별도의 비밀 정보를 전달받고 이를 통해 Domainkey 방식에서 사용하는 개인키/공개키 쌍을 생성하도록 하였으며 기존의 PGP 방식과도 접목하여 전자우편 송신자에 대한 인증 및 메시지에 대한 암복호화 기능을 수행하는 기법을 제안한다. 제안한 기법은 메일 발송 과정에서 발신자에 대한 인증 과정을 수행하므로 스팸 메일의 발송을 방지할 수 있는 기법이다.

• ETRI Journal
• /
• 제28권3호
• /
• pp.329-336
• /
• 2006

This paper investigates the problem of protecting multicast sessions in mesh wavelength-division multiplexing (WDM) networks against single link failures, for example, a fiber cut in optical networks. First, we study the two characteristics of multicast sessions in mesh WDM networks with sparse light splitter configuration. Traditionally, a multicast tree does not contain any circles, and the first characteristic is that a multicast tree has better performance if it contains some circles. Note that a multicast tree has several branches. If a path is added between the leave nodes on different branches, the segment between them on the multicast tree is protected. Based the two characteristics, the survivable multicast sessions routing problem is formulated into an Integer Linear Programming (ILP). Then, a heuristic algorithm, named the adaptive shared segment protection (ASSP) algorithm, is proposed for multicast sessions. The ASSP algorithm need not previously identify the segments for a multicast tree. The segments are determined during the algorithm process. Comparisons are made between the ASSP and two other reported schemes, link disjoint trees (LDT) and shared disjoint paths (SDP), in terms of blocking probability and resource cost on CERNET and USNET topologies. Simulations show that the ASSP algorithm has better performance than other existing schemes.

• Geomechanics and Engineering
• /
• 제28권6호
• /
• pp.613-624
• /
• 2022

A study of the evolution of overburden fractures under the solid-fluid coupling state was conducted based on the geological and mining characteristics of the coal seam depth, weak strata cementation, and high-intensity mining in the mining areas of West China. These mining characteristics are key to achieving water conservation during mining or establishing groundwater reservoirs in coal mines. Based on the engineering background of the Daliuta Coal Mine, a non-hydrophilic simulation material suitable for simulating the weakly cemented rock masses in this area was developed, and a physical simulation test was carried out using a water-sand gushing test system. The study explored the spatial distribution and dynamic evolution of the fractured zone in the mining overburden under the coupling of stress and seepage. The experimental results show that the mining overburden can be vertically divided into the overall migration zone, the fracture extension zone and the collapse zone; additionally, in the horizontal direction, the mining overburden can be divided into the primary fracture zone, periodic fracture zone, and stop-fracture zone. The scope of groundwater flow in the overburden gradually expands with the mining of coal seams. When a stable water inrush channel is formed, other areas no longer generate new channels, and the unstable water inrush channels gradually close. Finally, the primary fracture area becomes the main water inrush channel for coal mines. The numerical simulation results indicate that the overlying rock breaking above the middle of the mined-out area allows the formation of the water-conducting channel. The water body will flow into the fracture extension zone with the shortest path, resulting in the occurrence of water bursting accidents in the mining face. The experimental research results provide a theoretical basis for the implementation of water conservation mining or the establishment of groundwater reservoirs in western mining areas, and this theoretical basis has considerable application and promotion value.

• 정보관리연구
• /
• 제36권2호
• /
• pp.153-172
• /
• 2005

현재 저작권과 온라인 디지털 콘텐츠 산업발전법은 데이터베이스와 디지털 콘텐츠 제작자를 보호대상으로 하고 있다. 미국 데이터베이스 보고서의 추가 보호론에 데이터베이스는 경제 및 과학에 있어 그 중요성을 더해 가고 있으며, 인터넷 상의 핵심적 요소가 되어가고 있다. 그러므로 우리나라의 공공 민간 모두 데이터베이스의 법적 보호에 신중을 기해야 한다. 본 고에서는 과학기술 데이터베이스 법적 보호의 전반적인 문제점들과 현행법에 의한 과학기술 데이터베이스 보호의 핵심적인 내용과 추가적인 보호 문제를 깊이있게 다루었다. 과학기술 데이터베이스 산업의 발전이 국가의 경쟁력 확보에 중대한 몫을 차지하고 있다는 점을 고려할 때, 데이터베이스의 법적보호방안 마련은 데이터베이스의 지속적인 발전을 도모하기 위한 정책의 하나로서, 간과되어서는 안 될 중요한 사안 중의 하나이다.

• The Plant Pathology Journal
• /
• 제31권2호
• /
• pp.140-151
• /
• 2015

Bacillus subtilis B006 strain effectively suppresses the cucumber fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum (Foc). The population dynamics of Foc, strain B006 and its surfactin over-producing mutant B841 and surfactin-deficient mutant B1020, in the rhizosphere were determined under greenhouse conditions to elucidate the importance of the lipopeptides excreted by these strains in suppressing Foc. Results showed that B. subtilis strain B006 effectively suppressed the disease in natural soil by 42.9%, five weeks after transplanting, whereas B841 and B1020 suppressed the disease by only 22.6% and 7.1%, respectively. Quantitative PCR assays showed that effective colonization of strain B006 in the rhizosphere suppressed Foc propagation by more than 10 times both in nursery substrate and in field-infected soil. Reduction of Foc population at the cucumber stems in a range of $0.96log_{10}ng/g$ to $2.39log_{10}ng/g$ was attained at the third and the fifth weeks of B006 treatment in nursery substrate. In field-infected soil, all three treatments with B. subtilis suppressed Foc infection, indicated by the reduction of Foc population at a range of $2.91log_{10}ng/g$ to $3.36log_{10}ng/g$ at the stem base, one week after transplanting. This study reveals that the suppression of fusarium wilt disease is affected by the effective colonization of the surfactin-producing B. subtilis strain in the rhizosphere. These results improved our understanding of the biocontrol mechanism of the B. subtilis strain B006 in the natural soil and facilitate its application as biocontrol agent in the field.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2005년도 추계종합학술대회
• /
• pp.1011-1014
• /
• 2005

In this paper, we propose a method that extracts an invariant biometric key in order to apply this biometric key to the crypto-biometric system. This system is a new authentication architecture which can improve the security of current cryptographic system and solve the problem of stored template protection in conventional biometric system, also. To use biometric information as a cryptographic key in crypto-biometric system, same key should be generated from the same person. However, it is difficult to obtain such an invariant biometric key because biometric data is sensitive to surrounding environments. The proposed method solves this problem by clustering Iris Codes obtained by using independent component analysis (ICA).

• 한국통신학회논문지
• /
• 제27권3C호
• /
• pp.220-225
• /
• 2002

본 논문은 Mobile IP의 보안적인 측면에 대해 다룬다. 인증 기법과 재생공격 방지 기법을 사용함에도 불구하고 재생공격이 여전히 일어남을 보여주고 이를 해결하기 위해 공개키를 이용한 AAA에서의 새로운 등록방법과 세션키 분배 방법을 제안한다. 제안된 프로토콜은 이동노드의 인증이 완료됨과 동시에 session-key의 분배가 이루어지도록 설계하였다. 또한 공개키 시스템을 최소한으로 사용하여 재생공격의 문제점을 해결하였고 이동노드에서 최소의 계산량을 요구하도록 설계하였다. AAA에서의 정확한 accounting이 가능하도록 부인방지 기능도 추가하였다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 하계종합학술대회 논문집 I
• /
• pp.113-116
• /
• 2003

Mobile communication network because information through radio channel is passed, information may be eavesdropped and need information security countermeasure in communication network dimension for safe information exchange because there is possibility that is manufactured. This paper used Public Key Cryptography for protection and authentication connected with user authentication. Use public key and private key that is asymmetry encryption key to quote that is used at encryption, decryption of Public key. Encrypt IMSI and authentication message that is transmitted MS, VLR and HLR interval to public key, wish to embody transmitted authentication protocol safety.

• ETRI Journal
• /
• 제43권2호
• /
• pp.344-356
• /
• 2021

CRAFT is a tweakable block cipher introduced in 2019 that aims to provide strong protection against differential fault analysis. In this paper, we show that CRAFT is vulnerable to side-channel cube attacks. We apply side-channel cube attacks to CRAFT with the Hamming weight leakage assumption. We found that the first half of the secret key can be recovered from the Hamming weight leakage after the first round. Next, using the recovered key bits, we continue our attack to recover the second half of the secret key. We show that the set of equations that are solvable varies depending on the value of the key bits. Our result shows that 99.90% of the key space can be fully recovered within a practical time.

• Journal of information and communication convergence engineering
• /
• 제20권4호
• /
• pp.242-249
• /
• 2022

Classical cryptography with complex computations has recently been utilized in the latest computing systems to create secret keys. However, systems can be breached by fast-measuring methods of the secret key; this approach does not offer adequate protection when depending on the computational complexity alone. The laws of physics for communication purposes are used in quantum computing, enabling new computing concepts to be introduced, particularly in cryptography and key distribution. This paper proposes a quantum computing lattice (CQL) mechanism that applies the BB84 protocol to generate a quantum key. The generated key and a one-time pad encryption method are used to encrypt the message. Then Babai's algorithm is applied to the ciphertext to find the closet vector problem within the lattice. As a result, quantum computing concepts are used with classical encryption methods to find the closet vector problem in a lattice, providing strength encryption to generate the key. The proposed approach is demonstrated a high calculation speed when using quantum computing.