• Journal of Korea Society of Industrial Information Systems
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• v.15 no.3
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• pp.41-49
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• 2010

Recently, RFID systems are spreading in various industrial areas faster but cause some serious problems of information security because of its unstable wireless communication. Moreover, traditional RFID systems have a restriction that one tag per each application object. This restriction deteriorates their usability because it is difficult to distinguish many tags without some kind of effort. Therefore, efficient information sharing of objects based on information security has to be studied for more spreading of RFID technologies. In this paper, we design a new RFID tag structure for supporting multiple objects which can be shared by many different RFID applications. We also design an encryption/decryption algorithm to protect the identifying information of objects stored in our tag structure. This algorithm is a light revision of the existing SEED algorithm which can be operated in RFID tag environment. To evaluate the performance of our algorithm, we measure the encryption and decryption times of this algorithm and compare the results with those of the original SEED algorithm.

• Journal of Information Processing Systems
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• v.13 no.3
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• pp.573-589
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• 2017

Cloud computing is an attractive solution that can provide low cost storage and powerful processing capabilities for government agencies or enterprises of small and medium size. Yet the confidentiality of information should be considered by any organization migrating to cloud, which makes the research on relational database system based on encryption schemes to preserve the integrity and confidentiality of data in cloud be an interesting subject. So far there have been various solutions for realizing SQL queries on encrypted data in cloud without decryption in advance, where generally homomorphic encryption algorithm is applied to support queries with aggregate functions or numerical computation. But the existing homomorphic encryption algorithms cannot encrypt floating-point numbers. So in this paper, we present a mechanism to enable the trusted party to encrypt the floating-points by homomorphic encryption algorithm and partial trusty server to perform summation on their ciphertexts without revealing the data itself. In the first step, we encode floating-point numbers to hide the decimal points and the positive or negative signs. Then, the codes of floating-point numbers are encrypted by homomorphic encryption algorithm and stored as sequences in cloud. Finally, we use the data structure of DoubleListTree to implement the aggregate function of SUM and later do some extra processes to accomplish the summation.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.145-148
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• 2002

In a network communication process, cryptographic algorithms play important role for secure process. This paper presents a new system architecture named "DCCS." This system can handle flexible operations of both cryptographic algorithms and the keys. For experimental evaluation, two representative cryptographic algorithms DES and Triple-DES are designed and implemented into an FPGA chip on the SEBSW-1. Then the developed board is confirmed to change its cryptographic algorithms dynamically. Also its throughput confirmed the ability of the real-time net-work use of the designed system.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.9
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• pp.658-665
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• 2003

In this paper, we propose an improved image encryption and the shift-tolerance method in the Fourier space using a virtual phase image. The encrypted image is obtained by the Fourier transform of the product of a phase-encoded virtual image, not an original image, and a random phase image. Therefore, even if unauthorized users analyze the encrypted image, we can prevent the possibility of counterfeiting from unauthorized people using virtual image which dose not contain any information from the original image. The decryption technique is simply performed by inverse Fourier transform of the interference pattern between the encrypted image and the Fourier decrypting key, made of proposed phase assignment rule, in frequency domain. We demonstrate the robustness to noise, to data loss and shift of the encrypted image or the Fourier decryption key in the proposed technique.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.961-964
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• 2000

With the advance of wireless communications technology, mobile communications has become more convenient than ever. However because of the openness of wireless communications, how to protect the privacy between communicating parties is becoming a very important issue. In this paper an authentication and encryption algorithm of the GSM network for roaming user is proposed. In the proposed algorithms, we use a new hash function for user authentication and LFSR (Linear Feedback Shift Register) based stream cipher for message encryption and decryption. Each algorithm is programmed with C language and simulated on IBM-PC system and we analyze the randomness properties of the developed algorithm using statistical analysis.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.7 s.361
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• pp.71-80
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• 2007

This paper describes an efficient hardware design of WiBro security processor (WBSec) supporting for the security sub-layer of WiBro wireless internet system. The WBSec processor, which is based on AES (Advanced Encryption Standard) block cipher algorithm, performs data oncryption/decryption, authentication/integrity, and key encryption/decryption for packet data protection of wireless network. It carries out the modes of ECB, CTR, CBC, CCM and key wrap/unwrap with two AES cores working in parallel. In order to achieve an area-efficient implementation, two design techniques are considered; First, round transformation block within AES core is designed using a shared structure for encryption/decryption. Secondly, SubByte/InvSubByte blocks that require the largest hardware in AES core are implemented using field transformation technique. It results that the gate count of WBSec is reduced by about 25% compared with conventional LUT (Look-Up Table)-based design. The WBSec processor designed in Verilog-HDL has about 22,350 gates, and the estimated throughput is about 16-Mbps at key wrap mode and maximum 213-Mbps at CCM mode, thus it can be used for hardware design of WiBro security system.

• Journal of Convergence for Information Technology
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• v.9 no.1
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• pp.142-150
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• 2019

This study is a file management security system that encrypts and decrypts computer and cloud data by using Bluetooth based cryptographic module. It is a necessary solution in terms of abuse of personal information and protection of social and national information. We developed H/W and S/W for SFMS(: Safe File Management Security) related Bluetooth module in cloud environment and implemented firmware development, encryption key generation and issuance, client program for system mobile and key management system. In the terminal internal encryption and decryption, SFMS was developed to ensure high security that the hacking itself is not possible because key values exist separately for each file.

• The Transactions of the Korea Information Processing Society
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• v.4 no.6
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• pp.1565-1575
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• 1997

A new encryption algorithm had been proposed as a replacement to the Data Encryption Standard (DES) in [1,2]. It called the Extended DES (EDES) has a key length of 112 bits. The plaintext data consists of 96 bits divided into 3 sub-blocks of 32 bits each. The EDES has a potentially higher resistance to differential cryptanalysis that the DES due to the asymmetric number of f functions performed on each of the 3 sub-blocks and due to the increase of S-boxes from 8 to 16. This paper propose a hardware design for the EDES and its implementation in VLSI. The VLSI chip implements data encryption and decryption in a single hardware unit. With a system clock frequency of 15Mhz the device permits a data conversion rate of about 90Mbit/sec. Therefore, the chip can be applied to on-line encryption in high-speed networking protocols.

• Journal of Korea Multimedia Society
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• v.18 no.7
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• pp.818-826
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• 2015

With the rapid interest in Geographic Information System (GIS) contents, a large volume of valuable GIS dataset has been distributed illegally by pirates, hackers, or unauthorized users. Therefore the problem focus on how to protect the copyright of GIS vector map data for storage and transmission. But GIS vector map data is very large and current data encryption techniques often encrypt all components of data. That means we have encrypted large amount of data lead to the long encrypting time and high complexity computation. This paper presents the selective encryption scheme using hybrid transform for GIS vector map data protection to store, transmit or distribute to authorized users. In proposed scheme, polylines and polygons in vector map are targets of selective encryption. We select the significant objects in polyline/polygon layer, and then they are encrypted by the key sets generated by using Chaotic map before changing them in DWT, DFT domain. Experimental results verified the proposed algorithm effectively and error in decryption is approximately zero.

• 한국디지털정책학회:학술대회논문집
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• 2004.11a
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• pp.221-229
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• 2004

This paper aims at developing communication module and application prcgram for client management module and developing database management module and managing wireless communication facilities for server systems. To construct these aims, we have adapted DES algorithm and researched on encrypting and decrypting module development applicable to SMS Security System and optimize module size and processing speed.