• Journal of Korean Society of societal Security
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• v.2 no.4
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• pp.75-81
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• 2009

This paper presents the geotechnical characteristics of tunnel co \l apse based on the case studies. For domestic cases, most collapses are likely to happen along the weakest zone of shear strength due to the change of stresses induced by excavation specially when soft or weathered rock exist in front of a tunnel. In other words, the collapse of a tunnel occurs along the highly weathered fractured zone due to blasting and excavation. In Europe, collapses have been occurred by one joint group even though the ground is relatively fresh and for the rocks of which RQD is over 50%. In addition, the amount of ground water flow does not seem to be seriously affected by the RQD range.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8C
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• pp.633-641
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• 2008

Since WSNs encounter attacks, such as jamming or eavesdropping without physical access occurs, security is one of the important requirements for WSNs. The key pre-distribution scheme that was recently researched for advance of security in WSNs distributes the keys and probability with the use of q-composite random key pre-distribution method, but there is a high probability that no key shared between sensor nodes, and it takes a lot of time and energy to find out the shared key. Therefore, it is not suitable for WSNs. In order to enhance stability of a node that plays a role of gateway without depending on probabilistic key, this paper proposesa key pre-distribution scheme combined with random key pre-distribution scheme and double hash chain. Since the proposed scheme can maintain a small storage place and strong security strengths, it is more efficient than the existing schemes with the same security strengths. In addition, since it uses a small size of key generation key set, it can reduce a great deal of storage overhead.

• Convergence Security Journal
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• v.17 no.5
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• pp.143-151
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• 2017

The purpose of this study is to provide the future development of the PRC Marine Corps by analyzing the changing functions via its historical development. The PRCMC is an elite regular military forces and was established by the Central Military Commission(China) in 1953 in order to project the national military power toward the enemy's territory by overcoming maritime obstacles such as seas and lakes. The PRCMC is relatively smaller personnel strength compared with the whole size of the PRC military forces. Thus its functions were limited in the areas of amphibious and land operations, island and land defense against Taiwan before the PRC pursues expanding policy toward outside. However, in the 2000s, China pursues its policy for obtaining absolute national interest so that its functions are rapidly enlarged into defense of the forward naval bases, and those for evolving its power toward outside according to not only the island territorial dispute with Japan, but also Xi Jinping's active expanding policy what we call 'the one belt and one road'. So its personnel strength is slowly increased. If the increasement of the PRC Navy and Marine Corps would develop into the level of which they can contain the status and influence of the US military power in Asia-Pacific area, it is possible that the security environment of the North-east Asia including the Korean peninsula will be fluctuated. Consequently, the ROK also needs to reevaluate the functions and the size of the joint strength of the ROK Navy and Marine Corps considering the transition of the changing security environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4B
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• pp.695-703
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• 2010

In this paper, we propose an adaptive scalable encryption scheme for the layered architecture of SVC video. The proposed method determines an appropriate set of encryption algorithms to be applied for the layers of SVC by considering the importance and priority relationship among the SVC video layers. Unlike the conventional encryption method based on a fixed encryption algorithm for the whole video layers, the proposed method applies differentiated encryption algorithms with different encryption strength the importance of the video layers. Thereupon, higher security could be maintained for the lower video layer including more important data, while lower encryption strength could be applied for the higher video layer with relatively less important data. The effectiveness of the proposed adaptive scalable encryption method is proved by extensive simulations.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.3
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• pp.55-67
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• 2007

In ad hoc network, especially in the environment which the system authority only exists at the beginning of the network, it is very important problem how to issue the certificates in self-initialized public key scheme that a node generates its certificate with public and private key pair and is signed that by the system authority. In order to solve this problem, early works present some suggestions; remove the system authority itself and use certificate chain, or make nodes as system authorities for other nodes' certificates. In this paper, we suggest another solution, which can solve many problem still in those suggestions, using proxy signature and threshold signature, and prove its performance using simulation and analyse its security strength in many aspects.

• Convergence Security Journal
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• v.3 no.1
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• pp.73-84
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• 2003

The IPv4 that used to be generally used as a medium of computer communications in 1980s has reached its limits now. IPv6 (IP Version 6) is being prepared to solve the limitations of the IPv4. However, the biggest problem of IPv6 is that it is not compatible with the IPv4. To resolve the compatibility issue, Dual Stack, Tunneling and Header Converting methods have been proposed. The Header Converting method allows communications between the IPv4 and IPv6 networks with the converter. This method's strength is that it is easy to embody and the procedures for embodiment is simple. However, this method still contains the weaknesses that the existing IPv4 has. On the current document, the Header Converting method among the three methods is discussed to resolve the problems this method has. To solve the Header Converting method's weakness, the security problem between sections, the IP Header field values are converted to the relative field values and IPSec (IP Security) and ESP (Encapsulation Security Payload) are applied. The proposed "Encrypted Header Converting Method" that is encrypted in packet units has solved the weakness that the pre-existing Header Converting method used to have.d to have.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.165-168
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• 2005

The objects, which can be personal digital assistants, electronic rings, doors or even clothes, offer embedded chips with computation facilities and are generally called artifacts. I later realized that this was not so the real problem is actually authentication. Recent results indicate scalability problems for flat ad hoc networks. Sensor network achieves function that handle surrounding information perception through sensor and sensed information to network that is consisted of sensor nodes of large number. Research about new access control techniques and height administration techniques need authentication information persons' certification assurance level classification in sensor network environment which become necessary different view base with authentication information at node for application of AAA technology in USN environment that must do authentication process using information that is collected from various sensor mountings. So, get base authentication information in sensor type and present weight grant model by security strength about authentication information through information who draw. In this paper collected information of sensor nodes model who give weight drawing security reinforcement as authentication information by purpose present be going to. and Must be able to can grasp special quality of each sensor appliances in various side and use this and decide authentication assurance level for value estimation as authentication information elements. Therefore, do to define item that can evaluate Authentication information elements thus and give simple authentication assurance level value accordingly because applying weight. Present model who give authentication assurance level value and weight for quotation according to security strength.

• Current Optics and Photonics
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• v.3 no.2
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• pp.119-127
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• 2019

A new secret-key-sharing cryptosystem using optical phase-shifting digital holography is proposed. The proposed secret-key-sharing algorithm is based on the Diffie-Hellman key-exchange protocol, which is modified to an optical cipher system implemented by a two-step quadrature phase-shifting digital holographic encryption method using orthogonal polarization. Two unknown users' private keys are encrypted by two-step phase-shifting digital holography and are changed into three digital-hologram ciphers, which are stored by computer and are opened to a public communication network for secret-key-sharing. Two-step phase-shifting digital holograms are acquired by applying a phase step of 0 or ${\pi}/2$ in the reference beam's path. The encrypted digital hologram in the optical setup is a Fourier-transform hologram, and is recorded on CCDs with 256 quantized gray-level intensities. The digital hologram shows an analog-type noise-like randomized cipher with a two-dimensional array, which has a stronger security level than conventional electronic cryptography, due to the complexity of optical encryption, and protects against the possibility of a replay attack. Decryption with three encrypted digital holograms generates the same shared secret key for each user. Schematically, the proposed optical configuration has the advantage of producing a kind of double-key encryption, which can enhance security strength compared to the conventional Diffie-Hellman key-exchange protocol. Another advantage of the proposed secret-key-sharing cryptosystem is that it is free to change each user's private key in generating the public keys at any time. The proposed method is very effective cryptography when applied to a secret-key-exchange cryptosystem with high security strength.

• Journal of the Korea Society of Computer and Information
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• v.13 no.5
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• pp.95-102
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• 2008

The next generation network preparation of stock computer network designated to facilities and goal facilities-based national main information communication certainly necessary for 'national competitiveness enhancement and national economic strength elevations'. This paper studies current government policy and network, security and securities computer network, and substitute for securities computer network-based the existing SONET/SDH, and next generation securities computer network designs so as to provide ALL-IP service-based MPLS for international GMG service. Set up stability, standardization, security, a basis of and compare is current next generation securities computer network by each bases in case of designs. Analyze an expected effect to have been improved at next generation stock computer network characteristics and merits and substitution width and QoS, communication instrument liquor, an information protection system etc. too. Result of research of this paper will contribute to national competitiveness enhancement and a national economic strength elevation to accomplish u-Korea.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.3 s.303
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• pp.1-8
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• 2005

At IETF (Internet Engineering Task Force), recently RFC3775, RFC3776 documents about the mobile IPv6 were standardized by IETF (Internet Engineering Task Force). Those specifications propose that during the roaming, the mobile node sends securely the binding update to the home agent and the correspondent node after setting the security association between Mobile Node and Home Agent. But there is no secure bootstrapping method between a mobile node and a home agent at the two RFC documents. This paper proposed a method for the secure bootstrapping between a mobile node and a home agent. This makes the authentication, binding update, home agent assignment, security association distribution through the AAA-based secure channel between mobile node and home agent. And the proposed method was analyzed in the view of the procedure, round trip and security strength.