• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2019년도 춘계학술발표대회
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• pp.129-132
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• 2019

현재 양자컴퓨터 개발에 대한 전폭적인 연구가 이루어지고 있다. 지금의 양자컴퓨터의 개발수준은 기존 암호 시스템에 위협이 될 정도는 아니지만, 가까운 미래에 다가올 양자컴퓨터 시대에 대한 양자내성암호가 필요한 상황이다. 이에 양자내성암호 표준화를 위해 미국 NIST는 공모전을 열었고, 본 논문에서는 양자컴퓨터 개발현황과 NIST(National Institute of Standards and Technology) 양자내성암호 공모전의 암호알고리즘 설명과 동향을 살펴보고자 한다.

• 전자통신동향분석
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• 제33권6호
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• pp.94-106
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• 2018

A quantum key distribution (QKD) provides in principle an unconditional secure communication unlike the standard public key cryptography depending on the computational complexity. In particular, free-space QKD can give a secure solution even without a fiber-based infrastructure. In this paper, we investigate an overview of recent research trends in the free-space QKD system, including satellite and handheld moving platforms. In addition, we show the key components for a free-space QKD system such as the integrated components, single photon detectors, and quantum random number generator. We discuss the technical challenges and progress toward a future free- space QKD system and components.

• Journal of Information Processing Systems
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• 제15권1호
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• pp.203-216
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• 2019

The nature of wireless transmission has made wireless sensor networks defenseless against various attacks. This paper presents warning message counter method (WMC) to detect blackhole attack, grayhole attack and sinkhole attack in wireless sensor networks. The objective of these attackers are, to draw the nearby network traffic by false routing information and disrupt the network operation through dropping all the received packets (blackhole attack), selectively dropping the received packets (grayhole and sinkhole attack) and modifying the content of the packet (sinkhole attack). We have also attempted light weighted symmetric key cryptography to find data modification by the sinkhole node. Simulation results shows that, WMC detects sinkhole attack, blackhole attack and grayhole attack with less false positive 8% and less false negative 6%.

• International Journal of Computer Science & Network Security
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• 제21권7호
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• pp.205-210
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• 2021

In this paper, the possibility of using a contactless smart card as a cache for geocaching is analyzed. Geocaching is an outdoor game in which players search for hidden boxes, or caches based on geographical coordinates. The problems with this game are the possibility of players cheating and the need to maintain the caches. And then there is the problem of the ignorant public accidentally discovering a cache and considering it an explosive device. This paper proposes a concept for a possible solution to the above problems by replacing the boxes with conventional contactless smart cards. Also, this concept makes geocaching more attractive by using various games. This paper proposes a system architecture as well as the cryptographic protocol required for secure communication between the player's smartphone and the card.

• Computers and Concrete
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• 제34권1호
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• pp.79-91
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• 2024

In symmetric cryptography, a cryptographically secure Substitution-Box (S-Box) is a key component of a block cipher. S-Box adds a confusion layer in block ciphers that provide resistance against well-known attacks. The generation of a cryptographically secure S-Box depends upon its generation mechanism. In this paper, we propose a novel framework for the construction of cryptographically secure S-Boxes. This framework uses a combination of linear fractional transformation and permutation functions. S-Boxes security is analyzed against well-known security criteria that include nonlinearity, bijectiveness, strict avalanche and bits independence criteria, linear and differential approximation probability. The S-Boxes can be used in the encryption of any grayscale digital images. The encrypted images are analyzed against well-known image analysis criteria that include pixel changing rates, correlation, entropy, and average change of intensity. The analysis of the encrypted image shows that our image encryption scheme is secure.

• 한국정보통신학회논문지
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• 제18권1호
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• pp.11-17
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• 2014

ICT 생태계의 동인으로 전자정부는 그 형태의 변화를 가져온다. 이에 따라 스마트 전자정부 구현을 위해서 정부는 m-Gov 서비스를 활성화 하고, 이를 위해 기술정책을 수립할 필요가 있다. 따라서 본 논문에서 스마트 전자정부 구현 모형을 제시하고, 안전한 m-Gov의 인프라 구성을 위해 양자암호 시스템을 서버보안에 응용할 수 있는 정보보안 기술정책으로서 보안 알고리즘을 제안한다. 이것은 결국 보안성, 안전성, 경제성이 확보된 대국민 및 기업에 대한 스마트 전자정부 서비스를 제공하는 행정이념을 추구하는 것이다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권5호
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• pp.1343-1356
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• 2013

Cloud computing has emerged as perhaps the hottest development in information technology at present. This new computing technology requires that the users ensure that their infrastructure is safety and that their data and applications are protected. In addition, the customer must ensure that the provider has taken the proper security measures to protect their information. In order to achieve fine-grained and flexible access control for cloud computing, a new construction of hierarchical attribute-based encryption(HABE) with Ciphertext-Policy is proposed in this paper. The proposed scheme inherits flexibility and delegation of hierarchical identity-based cryptography, and achieves scalability due to the hierarchical structure. The new scheme has constant size ciphertexts since it consists of two group elements. In addition, the security of the new construction is achieved in the standard model which avoids the potential defects in the existing works. Under the decision bilinear Diffie-Hellman exponent assumption, the proposed scheme is provable security against Chosen-plaintext Attack(CPA). Furthermore, we also show the proposed scheme can be transferred to a CCA(Chosen-ciphertext Attack) secure scheme.

• 대한안전경영과학회지
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• 제9권3호
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• pp.103-109
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• 2007

Payment and security requirement are playing an increasingly critical role in RFID system, allegedly the core of the ubiquitous, especially in logistics. Therefore, security technology has been playing essential role gradually unlike the past when only the perception of equipment was considered important technology. The current encoding system allows the access only to the user who has the secret key. Many encoding algorithm has been studied to ensure the security of secret key. Security protocol is the most typical way to authorize appropriate user perception by using the data and secret key to proceed the encoding and transmit it to the system in order to confirm the user. However, RFID system which transmits more than dozens of data per second cannot be used if the algorithm and protocol of the existing wired system are used because the performance will degrade as a consequence. Security protocol needs to be designed in consideration of property of RFID and hardware. In this paper, a protocol was designed using SNEP(Sensor Network Encryption Protocol), the security protocol used for the sensor similar to RFID- not the current system used in wired environment- and ECC (Elliptic Curve Cryptography: oval curve encoding), the encoding algorithm.

• 한국군사과학기술학회지
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• 제17권3호
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• pp.358-363
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• 2014

In this paper, we present two constructions of the attribute-based broadcast encryption(ABBE) algorithm. Attribute-based encryption(ABE) algorithm enables an access control mechanism over encrypted data by specifying access policies among private keys and ciphertexts. ABBE algorithm can be used to construct ABE algorithm with revocation mechanism. Revocation has a useful property that revocation can be done without affecting any non-revoked uers. The main difference between our algorithm and the classical ones derived from the complete subtree paradigm which is apt for military hierarchy. Our algorithm improve the efficiency from the previously best ABBE algorithm, in particular, our algorithm allows one to select or revoke users by sending ciphertext of constant size with respect to the number of attributes and by storing logarithm secret key size of the number of users. Therefore, our algorithm can be an option to applications where computation cost is a top priority and can be applied to military technologies in the near future.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.404-406
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• 2015

128-비트 마스터키를 지원하는 블록암호 CLEFIA-128의 저면적 하드웨어 구현에 대해 기술한다. 라운드 키 생성을 위한 중간값 계산과 라운드 변환이 단일 데이터 프로세싱 블록으로 처리되도록 설계하였으며, 변형된 GFN(Generalized Feistel Network) 구조와 키 스케줄링 방법을 적용하여 데이터 프로세싱 블록과 키 스케줄링 블록의 회로를 단순화시켰다. Verilog HDL로 설계된 CLEFIA-128 프로세서를 FPGA로 구현하여 정상 동작함을 확인하였다. Vertex5 XC5VSX50T FPGA에서 823 slices로 구현되었으며, 최대 145 Mhz 클록으로 동작하여 105 Mbps의 성능을 갖는 것으로 예측되었다.