• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
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• pp.473-476
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• 2008

모바일 네트워크 환경은 언제 어디서나 네트워크를 사용하는 모바일 서비스를 편리하게 사용할 수 있도록 해준다. 그러나 모바일 단말기의 제약과 기존 무선 네트워크 환경의 보안 문제로 인하여 많은 보안 취약점을 가지고 있다. 이에 본 논문에서는 국내 모바일 표준 플랫폼인 WIPI에 세션키와 공개키를 조합함으로서 최소한의 암/복호화 연산을 수행하는 방식으로 PKI 서비스 구조를 제안하였다. 제안된 국내 표준 암호 알고리즘 기반의 안전한 인증 시스템은 모바일 네트워크 보안에 더욱 견고함을 더하여 줄 것이고, 향후 KISTI의 모바일 학술정보 콘텐츠 제공에 있어 안전한 서비스를 제공할 것이다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.485-487
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• 2017

국제 표준화 기구인 ISO/IEC에서 10118-3 표준으로 채택된 Whirlpool 해시 함수는 AES 블록 암호와 유사한 SPN(Substitution Permutation Network) 구조를 기반으로 하여 메시지의 무결성을 제공하는 알고리듬이다. 본 논문에서는 Whirlpool 해시 함수의 하드웨어 구현에 대해서 기술한다. 라운드 블록은 64-비트 데이터 패스로 설계하였으며, 10회의 라운드에 걸쳐서 암호화가 진행된다. 면적을 최소화하기 위해 키 확장과 암호화 알고리듬은 동일한 하드웨어를 사용한다. Verilog HDL을 이용해 Whirlpool 해시 함수를 모델링하였고, ModelSim으로 시뮬레이션을 수행하여 정상 동작을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권8호
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• pp.4006-4024
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• 2017

Internet of Things (IoT) will transform our daily life by making different aspects of life smart like smart home, smart workplace, smart health and smart city etc. IoT is based on network of physical objects equipped with sensors and actuators that can gather and share data with other objects or humans. Secure communication is required for successful working of IoT. In this paper, a total of 13 lightweight cryptographic algorithms are evaluated based on their implementation results on 8-bit, 16-bit, and 32-bit microcontrollers and their appropriateness is examined for resource-constrained scenarios like IoT. These algorithms are analysed by dissecting them into their logical and structural elements. This paper tries to investigate the relationships between the structural elements of an algorithm and its performance. Association rule mining is used to find association patterns among the constituent elements of the selected ciphers and their performance. Interesting results are found on the type of element used to improve the cipher in terms of code size, RAM requirement and execution time. This paper will serve as a guideline for cryptographic designers to design improved ciphers for resource constrained environments like IoT.

• 한국멀티미디어학회논문지
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• 제25권7호
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• pp.922-931
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• 2022

Recently, the need for health information management platforms has been increasing for efficient medical and IT technology research. However, health information is requiring security management by law. When permissioned blockchain technology is used to manage health information, the integrity is provided because only the authenticated users participate in bock generation. However, if the blockchain server is attacked, it is difficult to provide security because user authentication, block generation, and block verification are all performed on the blockchain server. In this paper, therefore, we propose a Health Information Management Server, which uses a permissioned blockchain algorithm and asymmetric cryptography. Health information is managed as a blockchain transaction to maintain the integrity, and the actual data are encrypted with an asymmetric key. Since using a private key kept in the institute local environment, the data confidentiality is maintained, even if the server is attacked. 1,000 transactions were requested, as a result, it was found that the server's average response time was 6,140ms, and the average turnaround time of bock generation was 368ms, which were excellent compared to those of conventional technology. This paper is that a model was proposed to overcome the limitations of permissioned blockchains.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권7호
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• pp.2286-2304
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• 2022

Blockchain is a distributed ledger that combines technologies such as cryptography, consensus mechanism, peer-to-peer transmission, and time stamping. The rapid development of blockchain has attracted attention from all walks of life, but storage scalability issues have hindered the application of blockchain. In this paper, a scalable blockchain storage model based on Distributed Hash Table (DHT) and the InterPlanetary File System (IPFS) was proposed. This paper introduces the current research status of the scalable blockchain storage model, as well as the basic principles of DHT and the InterPlanetary File System. The model construction and workflow are explained in detail. At the same time, the DHT network construction mechanism, block heat identification mechanism, new node initialization mechanism, and block data read and write mechanism in the model are described in detail. Experimental results show that this model can reduce the storage burden of nodes, and at the same time, the blockchain network can accommodate more local blocks under the same block height.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.246-248
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• 2022

Bernstein이 제안한 새로운 타원곡선 형태인 이진 에드워즈 곡선 (binary Edwards curves; BEdC)는 예외점이 없어 완전한 덧셈 법칙이 만족한다. 본 논문에서는 투영 좌표계를 적용한 BEdC 상의 점 스칼라 곱셈의 효율적인 하드웨어 구현에 대해 기술한다. 점 스칼라 곱셈을 위해 modified Montgomery ladder 알고리듬을 적용하였으며, 257-비트 이진 덧셈기와 이진 제곱기, 32-비트 이진 곱셈기를 사용하여 하위 이진체 연산을 구현했다. Zynq UltraScale+ MPSoC 디바이스에 구현하여 설계된 BEdC 크립토 코어를 검증하였으며, 점 스칼라 곱셈 연산에 521,535 클록 사이클이 소요된다.

• 전자통신동향분석
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• 제25권5호
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• pp.137-146
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• 2010

화이트박스 암호 기술이 소프트웨어 콘텐츠 저작권 보호(불법유출방지)를 위한 핵심 툴킷으로 등장하고 있다. 암호 알고리듬이 동작하는 단말과 단말의 사용자는 믿을 수 있다는 기존의 생각에서 최근에는 암호 알고리듬이 동작하는 단말은 오픈 플랫폼이 되어감에 따라 사용자가 모르는 사이 단말웨어가 설치되어 동작할 수도 있고, 사용자가 악의적인 목적으로 암호 알고리듬을 분석하고자 할 수도 있다는 인식이 퍼져가고 있다. 따라서 암호 알고리듬이 안전하게 동작하고, 암호 키의 불법유출을 막기 위한 하나의 방안으로 화이트박스 암호 기술이 등장하였다. 이 기술은 기존의 보안 하드웨어를 이용한 기술과는 달리 소프트웨어만으로 암호 알고리듬의 중간 연산값 및 암호화 키를 보호할 수 있다는 장점 외에도 다양한 장점을 보유하고 있으며, 암호 알고리듬의 화이트박스 구현 방법에 관한 연구가 활발히 진행되고 있다. 본 고에서는 화이트박스 암호 기술의 탄생 배경 및 화이트박스 암호 기술의 개념, 그리고 이를 이용한 응용 기술에 관해 기술하고자 한다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2019년도 추계학술대회
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• pp.165-168
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• 2019

The advancement in technology has led to the enormous use of multimedia applications. The video/image recorded by such applications provides critical information that can be used as a visual evidence. However, owing to the adequacy in using different editing tools, it is susceptible to malicious alterations. Thus, the reliability or the integrity of the visual information should be verified before using it as an evidence. In this paper, we propose an integrity verification method for the surveillance system using randomized hashing. The integrity value of the surveillance data is generated using the randomized hashing and elliptic curve cryptography (ECC), which is used later for the validation. The experimental results obtained from the embedded accident data recorder (ADR) system shows that the proposed method is very efficient and provides a high level of security.

• Journal of Information Technology Applications and Management
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• 제11권4호
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• pp.25-33
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• 2004

Recently, as network and computer technologies are growing rapidly, most of business transactions are performed in cyber world. In spite of many advantages, the most concerns in Electronic Commerce are the information security matters, and the cryptosystem has been claimed as one of the proper means to settle this problem. In this paper, a partial encryption/decryption algorithm has been in-troduced to show the efficiency against the conventional method in which all the data are completely encoded. In our proposed scheme, the multimedia data can be efficiently encoded in a short time providing good data security. For example, the MP3 data can be securely protected with 10% encryption in our scheme. Moreover, 1he shuffling process at the end of partial encryption procedure provides higher level of data security.

• ETRI Journal
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• 제30권5호
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• pp.707-717
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• 2008

This paper presents two types of high-speed hardware architectures for the block cipher ARIA. First, the loop architectures for feedback modes are presented. Area-throughput trade-offs are evaluated depending on the S-box implementation by using look-up tables or combinational logic which involves composite field arithmetic. The sub-pipelined architectures for non-feedback modes are also described. With loop unrolling, inner and outer round pipelining techniques, and S-box implementation using composite field arithmetic over $GF(2^4)^2$, throughputs of 16 Gbps to 43 Gbps are achievable in a 0.25 ${\mu}m$ CMOS technology. This is the first sub-pipelined architecture of ARIA for high throughput to date.