• International Journal of Computer Science & Network Security
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• 제21권12호
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• pp.248-256
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• 2021

Now that we're in the big data era, data has taken on a new significance as the storage capacity has exploded from trillion bytes to petabytes at breakneck pace. As the use of cloud computing expands and becomes more commonly accepted, several businesses and institutions are opting to store their requests and data there. Cloud storage's concept of a nearly infinite storage resource pool makes data storage and access scalable and readily available. The majority of them, on the other hand, favour a single cloud because of the simplicity and inexpensive storage costs it offers in the near run. Cloud-based data storage, on the other hand, has concerns such as vendor lock-in, privacy leakage and unavailability. With geographically dispersed cloud storage providers, multicloud storage can alleviate these dangers. One of the key challenges in this storage system is to arrange user data in a cost-effective and high-availability manner. A multicloud storage architecture is given in this study. Next, a multi-objective optimization problem is defined to minimise total costs and maximise data availability at the same time, which can be solved using a technique based on the non-dominated sorting genetic algorithm II (NSGA-II) and obtain a set of non-dominated solutions known as the Pareto-optimal set.. When consumers can't pick from the Pareto-optimal set directly, a method based on Principal Component Analysis (PCA) is presented to find the best answer. To sum it all up, thorough tests based on a variety of real-world cloud storage scenarios have proven that the proposed method performs as expected.

• 정보보호학회논문지
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• 제18권6A호
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• pp.51-61
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• 2008

본 논문은 최근 많이 사용되는 64-비트 프로세서인 Intel Core2 프로세서와 AMD Athlon64 프로세서에서 AES 알고리즘을 고속 구현하는 기법을 제시한다. 먼저 EM64T 아키텍처의 Core2 프로세서는 메모리 접근 명령어 처리 효율이 연산 명령어 처리 효율보다 떨어진다. 때문에 메모리 접근 명령어의 비율이 높게 구성된 기존 AES 구현기법은 메모리 병목현상이 발생된다. 이에 메모리 접근 명령어 비율을 낮춘 부분 라운드키 기법을 제시한다. ECB 모드로 구현한 결과 Core2Duo 3.0 Ghz 프로세서에서 185 cycles/block, 2.0 Gbps의 성능을 보여주었다. 이 결과는 가장 빠르다고 알려진 bernstein 코드보다 35 cycles/block 빠르다. 한편 AMD64 아키텍처의 Athlon64 프로세서에서는 명령어 디코딩 과정에서 발생하는 병목현상을 제거하므로써 속도를 향상시켰다. 그 결과 Athlon64 프로세서에서 170 cycles/block의 성능을 나타났다. 이는 가장 빠르다고 알려진 Matsui의 비공개 코드와 성능이 동일하다.

• 정보보호학회논문지
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• 제9권1호
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• pp.103-114
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• 1999

전자 상거래에 대한 다양한 프로토타입(prototype)이 구현되고 있고, 확대적용의 현실성이 증대되고 있는 작금의 상황을 반영하여 관련 연구가 활발해지고 있으며, 그 중에서 보다 안전하고 효율적인 전자지불방식에 대한 현실적 요구가 증대하고 있다. 전자지불방식의 하나인 전자화폐는 실물 화폐와 유사한 성질들을 만족해야 하며, 이러한 성질들 중에서 필수적인 익명성을 얻기 위한 방법으로는 D. Chaum이 제안한 Blind Signature가 대표적이다. 본 논문에서는 기존의 암호시스템들이 가지고 있는 계산량 등의 문제점을 극복할 수 있는 방식으로써 주목받고 있는 타원곡선 암호시스템 상에서 서명자와 피서명자 간에 은닉 요소(blinding factor)를 교환함으로써 익명성을 제공하는 Elliptic Curve Blind Signature 기법을 제안한다. 또한, 제안 방식을 이용한 전자화폐 프로토콜에서 화폐 잔액에 대한 서명자의 재서명 과정을 통해 화폐의 분할성을 얻는 방법을 제시한다.

• 한국항행학회논문지
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• 제16권5호
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• pp.871-878
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• 2012

64-비트 블록 암호 LBlock은 무선 센서 네트워크 환경과 같이 제한된 환경에 적합하도록 설계된 경량 블록 암호이다. 본 논문에서는 LBlock에 대한 차분 오류 공격을 제안한다. 랜덤 니블 오류 주입 가정에 기반을 둔 이 공격은 평균 5개의 랜덤 니블 오류와 $2^{25}$의 전수조사를 이용하여, LBlock의 비밀키를 복구한다. 이는 일반적인 수 초 내에 가능함을 의미한다. 본 논문의 공격 결과는 기제안된 LBlock에 대한 차분 오류 공격 결과보다 더 효율적이다.

• 디지털산업정보학회논문지
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• 제12권2호
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• pp.41-49
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• 2016

Lossless encryption methods are more applicable than lossy encryption methods when marginal distortion is not tolerable. In this research, the author propose a novel lossless symmetric key encryption/decryption technique. In the proposed algorithm, the image is transformed into the frequency domain using the lifting wavelet transform, then the image sub-bands are encrypted in a such way that guarantees a secure, reliable, and an unbreakable form. The encryption involves scattering the distinguishable frequency data in the image using a reversible weighting factor amongst the rest of the frequencies. The algorithm is designed to shuffle and reverse the sign of each frequency in the transformed image before the image frequencies are transformed back to the pixel domain. The results show a total deviation in pixel values between the original and encrypted image. The decryption algorithm reverses the encryption process and restores the image to its original form. The proposed algorithm is evaluated using standard security and statistical methods; results show that the proposed work is resistant to most known attacks and more secure than other algorithms in the cryptography domain.

• 응용통계연구
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• 제16권2호
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• pp.427-440
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• 2003

휴대전화, PDA와 같은 이동 단말기와 무선 통신의 발전으로 인하여, 이동 단말기를 이용한 전자 메일, 게임, 주식거래 등이 가능하게 되었다. 무선 단말기를 통한 주식거래나 게임 등을 위하여서는 난수발생기(Random Number Generator)의 사용이 필수적이다. 그런데 최근까지의 난수발생기는 우수한 난수성에 중점을 두어 개발되었으며, 이동 단말기에서의 에너지 소비량에 대한 연구는 없었다. 이동 단말기는 무게 및 크기의 한계 때문에 배터리의 용량에 제한이 있게되므로, 되도록 에너지 소비량을 줄여서 주어진 배터리를 오랫 동안 사용하기를 원하게 된다. 본 논문에서는 이동 단말기에서 많이 사용되는 여러 난수발생기들을 살펴보고, 저전력 에너지 측정도구인 SES(SNU Energy Scanner)를 이용하여 각 난수발생기의 에너지 소비량을 측정하여 이들을 비교한다. 이를 바탕으로 이동 단말기 환경에서 저전력을 소모하는 난수발생기를 제안하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권11호
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• pp.4224-4243
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• 2021

Cognitive radio (CR) is a feasible intelligent technology and can be used as an effective solution to spectrum scarcity and underutilization. As the key function of CR, cooperative spectrum sensing (CSS) is able to effectively prevent the harmful interference with primary users (PUs) and identify the available spectrum resources by exploiting the spatial diversity of multiple secondary users (SUs). However, the open nature of the cognitive radio networks (CRNs) framework makes CSS face many security threats, such as, the malicious user (MU) launches Byzantine attack to undermine CRNs. For this aim, we make an in-depth analysis of the motive and purpose from the MU's perspective in the interweave CR system, aiming to provide the future guideline for defense strategies. First, we formulate a dynamic Byzantine attack model by analyzing Byzantine behaviors in the process of CSS. On the basis of this, we further make an investigation on the condition of making the fusion center (FC) blind when the fusion rule is unknown for the MU. Moreover, the throughput and interference to the primary network are taken into consideration to evaluate the impact of Byzantine attack on the interweave CR system, and then analyze the optimal strategy of Byzantine attack when the fusion rule is known. Finally, theoretical proofs and simulation results verify the correctness and effectiveness of analyses about the impact of Byzantine attack strategy on the throughput and interference.

• 대한전자공학회논문지SD
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• 제41권9호
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• pp.73-84
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• 2004

본 논문에서는 하드웨어 상에 구현된 암호 프리미티브의 안전성을 위협할 수 있는 부채널 공격의 하나인 단순 전력 분석 (Simple Power Analysis)에 대응하는 알고리즘을 제안하고 이를 하드웨어로 구현하고자 한다. 제시하는 알고리즘은 기존에 알려진 대응 알고리즘보다 스칼라 곱셈 방법이 보다 효율적인 장점이 있다. 기존의 대응 알고리즘은 연산의 종속성 때문에 하드웨어의 장점인 병렬 처리 기법을 효율적으로 적용하기 어려운 단점이 존재한다. 이러한 단점을 보완코자 본 논문에서 제시하는 알고리즘은 동작 성능의 저하를 최소화하기 위해 역원 계산 시간 동안 곱셈 및 제곱 연산을 수행할 수 있도록 구성하였다. 또한 하드웨어 기술 언어인 VHDL(VHSIC Hardware Description Language)로 제안 알고리즘을 구현하여 성능 검증을 수행하였으며 이의 활용을 모색하였다. 하드웨어 합성은 Syplify pro7.0을 사용하였으며, 타겟 칩 Xillinx VirtexE XCV2000EFG1156을 대상으로 하였을 때 전체 등가 게이트는 60,608게이트, 최대 동작 주파수는 약 30Mhz로 산출되었다. 본 논문에서 제시한 스칼라 곱셈기는 전자 서명(Digital Signature), 암호화(Encryption) 및 복호화(Decryption), 키 교환(Key Exchange)등의 핵심 연산으로 사용될 수 있을 것으로 보이며, 자원 제약이 심한 Embedded-Micom 환경에 적용하였을 경우, 단순 전력 분석에 안전하면서 효율적인 연산 기능을 제공할 수 있을 것으로 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권10호
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• pp.4661-4680
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• 2016

Cognitive radio (CR) technology is an effective solution to the spectrum scarcity issue. Collaborative spectrum sensing is known as a promising technique to improve the performance of spectrum sensing in cognitive radio networks (CRNs). However, collaborative spectrum sensing is vulnerable to spectrum data falsification (SSDF) attack, where malicious users (MUs) may send false sensing data to mislead other secondary users (SUs) to make an incorrect decision about primary user (PUs) activity, which is one of the key adversaries to the performance of CRNs. In this paper, we propose a coalition based malicious users detection (CMD) algorithm to detect the malicious user in CRNs. The proposed CMD algorithm can efficiently detect MUs base on the Geary'C theory and be modeled as a coalition formation game. Specifically, SSDF attack is one of the key issues to affect the resource allocation process. Focusing on the security issues, in this paper, we analyze the power allocation problem with MUs, and propose MUs detection based power allocation (MPA) algorithm. The MPA algorithm is divided into two steps: the MUs detection step and the optimal power allocation step. Firstly, in the MUs detection step, by the CMD algorithm we can obtain the MUs detection probability and the energy consumption of MUs detection. Secondly, in the optimal power allocation step, we use the Lagrange dual decomposition method to obtain the optimal transmission power of each SU and achieve the maximum utility of the whole CRN. Numerical simulation results show that the proposed CMD and MPA scheme can achieve a considerable performance improvement in MUs detection and power allocation.

• International Journal of Computer Science & Network Security
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• 제22권1호
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• pp.331-339
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• 2022

The global process of transition from industrial to information society, as well as socio-economic changes taking place in Ukraine, require significant changes in many areas of state activity. It is especially connected with the reforms in the sphere of education. Today, national programs provide for the development of education on the basis of new progressive concepts, the introduction of the educational process of new pedagogical technologies and scientific achievements, the creation of a new system of information education, entrance of Ukaine into the transcontinental computer information system. Information technologies are qualitatively changing the key resources of development: this is no longer a space with fixed production, but primarily mobile finance and intelligence. They have a direct impact on the formation of personal growth, professional content and self-organization, emotional and psychological maturity and consciousness, and so on. One of the main factors in ensuring the stability and social education of the country's citizens is the culture of security, the formation and development of which is an urgent problem today. Comprehensive and systematic development of security culture will significantly increase the readiness of the population, the level of environmental, labor and patriotic education, reduce human losses, material damage from emergencies. Ecological education can be carried out more successfully only gradually and in accordance with the socio-psychological periods of one's development: kindergarten - school - college - university. The creation of such a system of environmental education should be enshrined as the basis of state environmental policy as a constitutional norm with the usage of information technology. Graduates of universities, who are the future of our country, after mastering the skills of basic environmental education must have a high level of environmental culture, which is, in turn, part of general human culture, and investigate environmental issues from the standpoint of their profession. It is known that with the help of environmental education the collective intelligence of society is formed, which can predict human activities and processes occurring in nature, and in some way to help with the elimination of crises. It is through environmental education that another system of human values is being formed, which places great emphasis on intangible wealth and solidarity, and great responsibility of humanity for the ecological state of the native country; provides a higher standard of living as a result of sustainable development, through the introduction of information technology in this system. To improve the quality of life, we need better knowledge, which must be implemented through information technology at the international level.