• Journal of the Korea Convergence Society
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• v.10 no.1
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• pp.25-33
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• 2019

The security of the data dealt by the smart city system is important because they have many privacy and public information. Therefore, it is necessary to study security in the smart city system. In this paper, we define the security factors for the smart city system composed of three tiers and describe the technologies for each. In addition, the design and implementation of the security layer in the Smart City middleware for the security management of the urban component in the Smart City Infrastructure and middleware, which is one of the most important issues in the Smart City system, is introduced.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.3
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• pp.143-155
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• 2006

ARIA is a 128-bit block cipher, which became a Korean Standard in 2004. According to recent research, this cipher is attacked by first order DPA attack. In this paper, we propose a new masking technique as a countermeasure against first order DPA attack and apply it to the ARIA. The proposed method is suitable for low memory environment. By using this countermeasure, we verified that it is secure against first order DPA attack. In addition, our method based on precomputation of inverse table can reduce the computational cost as increasing the number of S-BOX masking.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.5
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• pp.899-914
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• 2022

A blockchain-based decentralized service can offer reliable services without the centralized server by operating the system based on the consensus among byzantine participants. Participants can interact with the blockchain network through a digital signature mechanism but the private key management issue remains unresolved. NIST SP800-57 provides a key-management guidance but this guidance is not appropriate for blockchain-based services because it does not consider a decentralized environment. In this paper, we define the core functions of the blockchain wallet application for private key management and present security protections according to NIST SP800-57, as well as related techniques to satisfy them. Finally, we propose the private key management guideline for secure blockchain-based decentralized services.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.99-106
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• 2011

The emerging of ubiquitous computing and healthcare technologies provides us a strong platform to build sustainable healthcare applications especially those that require real-time information related to personal healthcare regardless of place. We realize that system stability, reliability and data protection are also important requirements for u-healthcare services. Therefore, in this paper, we designed a u-healthcare system which can be attached to the patient's body to measure vital signals, enhanced with USN secure sensor module. Our proposed u-healthcare system is using wireless sensor modules embedded with NLM-128 algorithm. In addition, PS-LFSR technique is applied to the NLM-128 algorithm to enable faster and more efficient computation. We included some performance statistical results in term of CPU cycles spent on NLM-128 algorithm with and without the PS-LFSR optimization for performance evaluation.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.299-308
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• 2014

Today, a number of users using smartphone is very rapidly increasing by development of smartphone performance and providing various services. Also, they are using it for enjoying various services(cloud service, game, banking service, mobile office, etc.). today's mobile security solution is simply to detect malicious code or stay on the level of mobile device management. In particular, the services which use sensitive information, such as certificate, corporation document, personal credit card number, need the technology which are prevented from hacking and leaking it. Recently, interest of these mobile security problems are increasing, as the damage cases been occurred. To solve the problem, there is various security research such as mobile virtualization, ARM trustzone, GlobalPlatform for mobile device. Therefore, in this paper, I suggested efficient method that uses the mobile virtualization techniques of certification, security policy and access control, password/key management, safe storage, etc. and Trustzone of ARM for preventing information leakage and hacking.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.9
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• pp.707-714
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• 2013

IoT, which can be regarded as an enhanced version of M2M communication technology, was proposed to realize intelligent thing to thing communications by utilizing Internet connectivity. Things in IoT are generally heterogeneous and resource constrained. Also such things are connected with each other over LLN(low power and lossy Network). Confidentiality, mutual authentication and message origin authentication are required to make a secure service in IoT. Security protocols used in traditional IP Networks cannot be directly adopted to resource constrained devices in IoT. Under the respect, a IETF standard group proposes to use lightweight version of DTLS protocol for supporting security services in IoT environments. However, the protocol can not cover up all of very constrained devices. To solve the problem, we propose a scheme which tends to support mutual authentication and session key agreement between devices that contain only a single crypto primitive module such as hash function or cipher function because of resource constrained property. The proposed scheme enhances performance by pre-computing a session key and is able to defend various attacks.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.5
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• pp.67-77
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• 2006

Radio Frequency IDentification (RFID) will soon become an important technology in various industries. Therefore, security mechanisms for Rm systems are emerging crucial problems in RFID systems. In order to guarantee privacy and security, it is desirable to encrypt the transferred data with a strong crypto algorithm. In this paper, we present the ultra-light weight Advanced Encryption Standard (AES) processor which is suitable for RFID tags. The AES processor requires only 3,992 logic gates and is capable of both 128-bit encryption and decryption. The processor takes 446 clock cycles for encryption of a 128-bit data and 607 clock cycles for decryption. Therefore, it shows 55% improved result in encryption and 40% in decryption from previous cases.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.4
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• pp.372-381
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• 2001

In this paper SEED, the Korea Standard 128-bit block cipher algorithm is implemented with VHDL and mapped into one FPGA. SEED consists of round key generation block, F function block, G function block, round processing block, control block and I/O block. The designed SEED is realized in an FPGA but we design it technology-independently so that ASIC or core-based implementation is possible. SEED requires many hardware resources which may be impossible to realize in one FPGA. So it is necessary to minimize hardware resources. In this paper only one G function is implemented and is used for both the F function block and the round key block. That is, by using one G function sequentially, we can realize all the SEED components in one FPGA. The used cell rate after synthesis is 80% in Altem FLEXI0KlOO. The resulted design has 28Mhz clock speed and 14.9Mbps performance. The SEED hardware is technology-independent and no other external component is needed. Thus, it can be applied to other SEED implementations and cipher systems which use SEED.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.55-60
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• 2019

It is true that Blockchain has been known as a core technology for cryptocurrency like bitcoin (BTC). It is caused by its rapid value rises. Now, one BTC is trading around 10,000 US dollars while it bought just less than one dollar at its first trading in May, 2010. Blockchain makes on-line transactions possible by the safe cryptocurrency swiftly based on P2P network and distributed public ledger while its on-line traffic is rapidly increasing. However, this technology has bigger potential in the fourth industrial revolution era and its application areas will be varied. The evolving intelligent information society needs to make new added value through utilizing, sharing and processing of useful digital information. Obstacles such as hacking and fraud often exist when transactions of digital properties, right transfers, etc. are done through digital network specialized with anonymity. It is expected that blockchain will be a definite solution in this regard. This paper addresses useful development directions and countermeasures for blokchain in the digital economy by analysis of its current status and issues.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.3
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• pp.65-76
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• 2005

Speeding up scalar multiplication of an elliptic curve point has been a prime approach to efficient implementation of elliptic curve schemes such as EC-DSA and EC-ElGamal. Koblitz introduced a $base-{\phi}$ expansion method using the Frobenius map. Kobayashi et al. extended the $base-{\phi}$ scalar multiplication method to suit Optimal Extension Fields(OEF) by introducing the table reference method. In this paper we propose an efficient scalar multiplication algorithm on elliptic curve over OEF. The proposed $base-{\phi}$ scalar multiplication method uses an optimized batch technique after rearranging the computation sequence of $base-{\phi}$ expansion usually called Horner's rule. The simulation results show that the new method accelerates the scalar multiplication about $20\%{\sim}40\%$ over the Kobayashi et al. method and is about three times as fast as some conventional scalar multiplication methods.