• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.5
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• pp.49-57
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• 2010

The fault cryptanalysis is a physical attack in which the key stored inside of the device can be extracted by occurring some faults when the device performs cryptographic algorithm. Since the international signature standard DSA(Digital Signature Algorithm) was known to be vulnerable to some fault analysis attacks, many researchers have been investigating the countermeasure to prevent these attacks. In this paper we propose a new countermeasure to compute DSA signature that has its immunity in the presence of faults. Since additional computational overhead of our proposal is only an inverse operation in signature process, the proposed DSA scheme can be implemented more efficiently compared to previous countermeasures.

• Journal of Advanced Marine Engineering and Technology
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• v.15 no.2
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• pp.44-52
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• 1991

The crankshaft system of engine is a complex vibratory object and its vibration modes are consisted of torsional, axial and their coupled vibration. Among them, the torsional vibration causes engine noise as well as serious fatigue faillures of crankshaft. If the troules of noises and crankshaft strength are forecasted by torsional vibration calculation in the design atage of crankshaft, the torsional damper is adopted as the final countermeasure. In this paper, some computer program to calculate crankshaft torsional vibration of engine are developed and with developed programs, an efficient rubber-viscous damper for automobile and with developed programs, an efficient rubber-viscous damper for automobile engine is designed and manufactured, and then it is fitted on the actual automobile engine to confirm its calculated efficiency. By comparing the measured result (with damper and without damper) with the calculated one, the reliability of developed computer programs and the performances of manufactured damper are confirmed.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.3
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• pp.317-324
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• 2009

Tactical Information Communication Network(TICN) uses both a wireless and wired network. To support mobility in battlefield environments, the application of Ad-hoc networking technology to its wireless communication has been examined. However, Ad-hoc network is faced to many security threats due to its intrinsic characteristics. Therefore, to apply the Ad-hoc networking technology to battlefield environments and TICN, an intensive study on security countermeasure must go side by side with the development of enabling technology. In this paper, we suggest an efficient key management scheme for TICN of which the Ad-hoc networking technology is applied.

• ETRI Journal
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• v.34 no.3
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• pp.482-484
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• 2012

With the rapid progress of wireless mobile communications, the authenticated key agreement (AKA) protocol has attracted an increasing amount of attention. However, due to the limitations of bandwidth and storage of the mobile devices, most of the existing AKA protocols are not suitable for wireless mobile communications. Recently, Lo and others presented an efficient AKA protocol based on elliptic curve cryptography and included their protocol in 3GPP2 specifications. However, in this letter, we point out that Lo and others' protocol is vulnerable to an offline password guessing attack. To resist the attack, we also propose an efficient countermeasure.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.581-584
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• 2008

This study analyzed activity of rockfall and its effect factor by the shape and mass. We performed research on the kinetic energy distribution, velocity and bounce height according to the rockfall characteristics using rockfall simulation program in cut-slope. In addition, this study discussed how to utilize kinetic energy and bounce height of rockfall for efficient establishment of rockfall prevention fence which is a countermeasure to cut-slope.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.556-560
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• 2004

The recent increase of the construction business. reflects tile rapid increase of the amounts of construction wastes caused by new buildings and demolitions. This trend brings about a problem of insufficient aggregate in the construction arena because construction wastes from new buildings are usually reclaimed in the land and it causes environmental pollution and a restriction of exploiting a natural aggregate, brought up by environmental organizations as well. Accordingly, researchers suggest recycled aggregate as a countermeasure of the two problems, however, it's not actually been used in the construction fields. By this study, it'll be feasible to expect to solve the problem of insufficient aggregate and to reduce environmental pollution from waste-reclamation.

• Journal of Advanced Marine Engineering and Technology
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• v.16 no.5
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• pp.85-96
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• 1992

Engine enclosures are widely adopted to reduce the noise emission in various fields of application. The radiated noise, which is due to the vibration of enclosure's outer surface, is composed of two kinds of sound power with different path of propagation. One is the 'structure-borne sound power' which stems from the engine's vibratory force applied to the structure of enclosure through the mounting parts of engine etc., while the other is the 'air-borne sound power' which is originated by the sound power radiated from the engine surface to the inner space of enclosure that should excite the vibration of enclosure from inside. In order to get a most efficient engine enclosure is required a profound consideration upon the above structure-borne and air-borne noise, since the guiding principle of countermeasure for each noise is quite different. The controlling of input vibration and its isolation are major subject for the structure-borne sound power and the specifications of absorbing member and damping panels are the major interests for the air-borne sound power. Hence it seems very efficient to separate the total sound power into two categories with a great accuracy when one think of further reduction of engine noise from the exciting enclosure, however, its separating methods have not been made clear for many years. Then author proposes a new practical separation method of two propagation path's contribution to the total radiation sound power for the enclosure under the engine operating condition.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.6
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• pp.77-85
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• 2013

The efficient operation and management strategies of reservoirs in irrigation periods of drought events are an essential element for drought planning and countermeasure. Korea Rural Community Corporation has developed the real-time water level observation system of agricultural reservoirs to efficiently operate reservoirs, however, it is not possible to predict drought conditions, and only provides information of current situation. Hence, it is necessary to evaluate accurate irrigation vulnerability and efficiently reservoir operation rules using current water level. In this paper, the improvement methods of reservoir operation planning were developed with water supply vulnerability characteristic curves comparing to automatic water gauge at agricultural reservoirs. The 11 reservoirs were simulated applying the reservoir operation rules which was determined by irrigation vulnerability characteristic curves criteria and real time water level, and evaluated water supply situation in 2012 year. The analysis of results can be identified probabilistic possibility of water supply failures compared with the existing reservoir operation criteria. These results of efficient reservoir operation rules can be achieved enable irrigation planners to optimally manage available water resources for decision making, and contributed to maintain the water supply according to demand strategy for agricultural reservoirs management.

• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.375-384
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• 2005

As the development of information communication technology and thus the growth of security incidents, there has been increasing demand on developing methodologies and tools for measuring the information security level of organizations for the efficient security management. However, most works from foreign countries are not realistic in constructing the checklists, moreover their tools provide neither the ease of use nor the inexpensiveness, and most domestic works are not properly considering the characteristics of the organizations when measuring the information security level. In this study, an efficient information security levelling tool is suggested, which applies the multiple variable weights for security levelling according to the characteristics of organizations and the fuzzy technique to reduce the user's subjectivity and the genetic algorithm to establish the security countermeasure.

• ETRI Journal
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• v.33 no.2
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• pp.267-274
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• 2011

This paper proposes an efficient masking method for the block cipher SEED that is standardized in Korea. The nonlinear parts of SEED consist of two S-boxes and modular additions. However, the masked version of these nonlinear parts requires excessive RAM usage and a large number of operations. Protecting SEED by the general masking method requires 512 bytes of RAM corresponding to masked S-boxes and a large number of operations corresponding to the masked addition. This paper proposes a new-style masked S-box which can reduce the amount of operations of the masking addition process as well as the RAM usage. The proposed masked SEED, equipped with the new-style masked S-box, reduces the RAM requirements to 288 bytes, and it also reduces the processing time by 38% compared with the masked SEED using the general masked S-box. The proposed method also applies to other block ciphers with the same nonlinear operations.