• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1652-1659
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• 2008

With the increase of huge amount of data in network systems, ultimate high-speed network has become an essential requirement. In such systems, the encryption and decryption process for security becomes a bottle-neck. For this reason, the need of hardware implementation is strongly emphasized. In this study, a mixed inner and outer round pipelining architecture is introduced to achieve high speed performance of ARIA hardware. Multiplexers are used to control the lengths of rounds for 3 types of keys. Merging of encryption module and key initialization module increases the area efficiency. The proposed hardware architecture is implemented on reconfigurable hardware, Xilinx Virtex2-pro. The hardware architecture in this study shows that the area occupied 6437 slices and 128 BRAMs, and it is translated to throughput of 24.6Gbit/s with a maximum clock frequency of 192.9MHz.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.331-332
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• 2018

일반적으로 정보를 전달함에 있어 정보의 유출은 큰 문제이다. 정보를 전달하는 방법이 발달하고 보편화됨에 따라 오늘날에 와서는 개인정보 유출과 관련된 문제가 지속적으로 대두되었다. 개인정보의 보호가 더욱 중요하게 생각되는 현 상황을 고려하여 스크래치(Scratch)의 기본 연산기능을 이용한 한글과 특수문자, 영어 암호화(Encryption) 및 복호화(Decryption)를 가능하게 하고, 정수 형태의 2개의 개인키와 간단한 알고리즘을 통해 암호문을 생성하는 어플리케이션을 통해 암호화와 복호화에 대한 개념을 학습하고, 더욱 나아가 개인정보 보호에 대한 중요성을 상기할 수 있도록 하였다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.2
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• pp.64-69
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• 2010

This paper designs the ABC(Advanced Block Cipher) algorithm which is a 64byte block encryption algorithm, improves the performance of encryption process time, and makes an key exchange using EC-DH. The ABC algorithm reduces basic memory occupation rates using the original data position exchange method which is a data swap key without S-Box, IP-Box and etc. Also, it prepares the exposure of symmetric key using the unfixed encryption(decryption) key excepting the fixed encryption(decryption) key. Therefore, the proposed ABC algorithm in this paper is a proper encryption algorithm in lower memory environment and mobile banking.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.925-938
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• 2010

Depending on network conditions, a communication network could be overloaded when media are transmitted. Research has been carried out to lessen network overloading, such as by filtering, load distribution, frame dropping, and other methods. Among these methods, one of the most effective is frame dropping, which reduces specified video frames for bandwidth diminution. In frame dropping, B-frames are dropped and then I- and P-frames are dropped, based on the dependency among the frames. This paper proposes a scheme for protecting copyrights by encryption, when frame dropping is applied to reduce the bandwidth of media based on the MPEG-4 file format. We designed two kinds of frame dropping: the first stores and then sends the dropped files and the other drops frames in real time when transmitting. We designed three kinds of encryption methods using the DES algorithm to encrypt MPEG-4 data: macro block encryption in I-VOP, macro block and motion vector encryption in P-VOP, and macro block and motion vector encryption in I-, P-VOP. Based on these three methods, we implemented a digital rights management solution for MPEG-4 data streaming. We compared the results of dropping, encryption, decryption, and the quality of the video sequences to select an optimal method, and found that there was no noticeable difference between the video sequences recovered after frame dropping and the ones recovered without frame dropping. The best performance in the encryption and decryption of frames was obtained when we applied the macro block and motion vector encryption in I-, P-VOP.

• Journal of the Korea Computer Industry Society
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• v.9 no.2
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• pp.39-46
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• 2008

In this study, investigated principle of encryption theoretically for plaintext and image encryption. Encryption method does character substitution(permutation cipher or transposition cipher) simply past in encryption method or had been used by method to move, but mode to use key stream generator present is used. That is, creating key in plaintext and encryption/decryption. That is, system of encryption according to method that create key changes. Investigate principle and a tool of encryption in treatise that see therefore, and representatively, investigated encryption principle under XOR operator and key stream generator condition.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1332-1340
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• 2007

This paper describes an efficient hardware design of key wrap/unwrap algorithm for security layer of WiBro system. The key wrap/unwrap core (WB_KeyWuW) is based on AES (Advanced Encryption Standard) algorithm, and performs encryption/decryption of 128bit TEK (Traffic Encryption Key) with 128bit KEK (Key Encryption Key). In order to achieve m 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 by using field transformation technique. As a result, the gate count of the WB_KeyWuW core is reduced by about 25% compared with conventional LUT (Lookup Table)-based design. The WB_KeyWuW con designed in Verilog-HDL has about 14,300 gates, and the estimated throughput is about $16{\sim}22-Mbps$ at 100-MHz@3.3V, thus the designed core can be used as an IP for the hardware design of WiBro security system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2698-2717
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• 2019

This paper proposes a multi-stage encryption technique to enhance the level of secrecy of image to facilitate its secured transmission through the public network. A great number of researches have been done on image secrecy. The existing image encryption techniques like visual cryptography (VC), steganography, watermarking etc. while are applied individually, usually they cannot provide unbreakable secrecy. In this paper, through combining several separate techniques, a hybrid multi-stage encryption technique is proposed which provides nearly unbreakable image secrecy, while the encryption/decryption time remains almost the same of the exiting techniques. The technique consecutively exploits VC, steganography and one time pad (OTP). At first it encrypts the input image using VC, i.e., splits the pixels of the input image into multiple shares to make it unpredictable. Then after the pixel to binary conversion within each share, the exploitation of steganography detects the least significant bits (LSBs) from each chunk within each share. At last, OTP encryption technique is applied on LSBs along with randomly generated OTP secret key to generate the ultimate cipher image. Besides, prior to sending the OTP key to the receiver, first it is converted from binary to integer and then an asymmetric cryptosystem is applied to encrypt it and thereby the key is delivered securely. Finally, the outcome, the time requirement of encryption and decryption, the security and statistical analyses of the proposed technique are evaluated and compared with existing techniques.

• Journal of the Korea Convergence Society
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• v.2 no.2
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• pp.13-19
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• 2011

When the existing mail system is attacked by the third party, its content is exposed fully. To solve this problem, designed is the mail encryption system which can send and receive mail safely by the sessionkey. The mail receiver opens encrypted mail with the session key. In the traditional mail system, the server administrator can view mail content. However, in the proposed protocol, the server can only save mail as encryption/decryption is applied. Also, the ARIA encryption algorithm is used in encryption/decryption for better safety, and fast XOR operations are used to reduce the amount of operations.

• Journal of the Optical Society of Korea
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• v.20 no.3
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• pp.341-357
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• 2016

A novel asymmetric multiple-image encryption method using an octonion Fresnel transform (OFST) and a two-dimensional Sine Logistic modulation map (2D-SLMM) is presented. First, a new multiple-image information processing tool termed the octonion Fresneltransform is proposed, and then an efficient method to calculate the OFST of an octonion matrix is developed. Subsequently this tool is applied to process multiple plaintext images, which are represented by octonion algebra, holistically in a vector manner. The complex amplitude, formed from the components of the OFST-transformed original images and modulated by a random phase mask (RPM), is used to derive the ciphertext image by employing an amplitude- and phase-truncation approach in the Fresnel domain. To avoid sending whole RPMs to the receiver side for decryption, a random phase mask generation method based on SLMM, in which only the initial parameters of the chaotic function are needed to generate the RPMs, is designed. To enhance security, the ciphertext and two decryption keys produced in the encryption procedure are permuted by the proposed SLMM-based scrambling method. Numerical simulations have been carried out to demonstrate the proposed scheme's validity, high security, and high resistance to various attacks.