• 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.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.3
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• pp.34-40
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• 2002

In this paper, a new encryption method for a binary image using Phase modulation and Fourier transform is proposed. For decryption we use the characteristics of square law detector. In encryption process, a key image is obtained by phase modulation of 256 level random pattern and its Fourier transformation, and input image is encrypted by Fourier transforming the multiplication of the phase modulated random pattern and phase modulated input image. The encrypted image and key image have only phase information, so they can not be copied or counterfeited and the original image can not be decrypted without the key image. To reconstruct the original image, each phase mask of the key image and the encrypted image must be placed on each path of the Mach-Zehnder interferometry with Fourier transform lens and the output image is obtained in the form of intensity in the CCD(Charge Coupled Device) camera. The real-time decryption is possible in the proposed system by use of a LCD as a phase modulator and a CCD camera as an intensity detector. The proposed method shows a good performance in the computer simulation and optical experiment as an encryption scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.9
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• pp.4487-4511
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• 2018

A fast image encryption system based on substitution and diffusion was proposed, which includes one covering process, one substitution process and two diffusion processes. At first, Chen's chaotic system together with an external 256-bit long secret key was used to generate the key streams for image encryption, in which the initial values of Chen's chaotic system were regarded as the public key. Then the plain image was masked by the covering process. After that the resulting image was substituted with the disturbed S-Box of AES. Finally, the substituted image was diffused twice with the add-modulo operations as the core to obtain the cipher image. Simulation analysis and comparison results with AES and some existing image cryptosystems show that the proposed image cryptosystem possesses the merits of fast encryption/decryption speed, good statistical characteristics, strong sensitivity and etc., and can be used as a candidate system of network security communication.

• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.833-836
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• 2007

Nowadays, the rapid increase of the available amount of internet and system performance has revealed urgent need a method of decryption about digital encryption for stabilization of multimedia data transmission. In this paper, we propose a method of decryption of each frame about video data. Also for advanced decryption, we propose color image decryption method through 4-bit binary of $GF(2^m)$ inverse about an each frame.

• Journal of information and communication convergence engineering
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• v.13 no.4
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• pp.280-285
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• 2015

Double random phase encryption (DRPE) is one of the well-known optical encryption techniques, and many techniques with DRPE have been developed for information security. However, most of these techniques may not solve the fundamental security problem caused by using fixed phase masks for DRPE. Therefore, in this paper, we propose a key phase mask updating scheme for DRPE to improve its security, where a spatial light modulator (SLM) is used to implement key phase mask updating. In the proposed scheme, updated key data are obtained by using previous image data and the first phase mask used in encryption. The SLM with the updated key is used as the second phase mask for encryption. We provide a detailed description of the method of encryption and decryption for a DRPE system using the proposed key updating scheme, and simulation results are also shown to verify that the proposed key updating scheme can enhance the security of the original DRPE.

• The Journal of Society for e-Business Studies
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• v.7 no.1
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• pp.167-186
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• 2002

The encryption of a file on a PC before saving can maintain security of the file. However, if the key for the encrypted file is lost or damaged, the encrypted file can not be decrypted, resulting in serious economical loss to the user or the user group. In order to minimize the economical loss a secure and reliable key recovery technology is required. Presented in this paper is the development and evaluation of PKRS (PC based Key Recovery System) which supports encryption and decryption of file and recovery of the encrypted file in emergency. The encapsulating method, which attaches key recovery information to encrypted file, is applied to the PKRS. In addition, the PKRS is developed and evaluated according to the requirements of Requirements for Key Recovery Products proposed by NIST and requirements of Common Criteria 2.0 to prove the safety and reliability of the information security system. This system is applicable to a PC and can be further extended to internet or intranet environment information system where in encryption and recovery of file is possible.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.811-819
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• 2012

In this paper, we design searchable image encryption system to provide the privacy and authentication on streaming media based on cloud computing. The searchable encryption system is the matrix of searchable image encryption system by extending the streaming search from text search, the search of the streaming service is available, and supports personal privacy and authentication using encryption/decryption and CBIR technique. In simple simulation of post-cut and image keyword creation, we can verify the possibilities of the searchable image encryption system based on streaming service.

• Journal of Korea Multimedia Society
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• v.16 no.10
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• pp.1156-1162
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• 2013

Face verification has been widely studied during the past two decades. One of the challenges is the rising concern about the security and privacy of the template database. In this paper, we propose a secure face verification system which generates a unique secure cryptographic key from a face template. The face images are processed to produce face templates or codes to be utilized for the encryption and decryption tasks. The result identity data is encrypted using Advanced Encryption Standard (AES). Distance metric naming hamming distance and Euclidean distance are used for template matching identification process, where template matching is a process used in pattern recognition. The proposed system is tested on the ORL, YALEs, and PKNU face databases, which contain 360, 135, and 54 training images respectively. We employ Principle Component Analysis (PCA) to determine the most discriminating features among face images. The experimental results showed that the proposed distance measure was one the promising best measures with respect to different characteristics of the biometric systems. Using the proposed method we needed to extract fewer images in order to achieve 100% cumulative recognition than using any other tested distance measure.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.6
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• pp.271-288
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• 2010

In this paper, we study the dysfunctions of cryptography as dual-use goods and national domestic encryption control policies like key recovery system and decryption order. And we examine risks of the breach of the peoples' constitutional rights like the right to privacy in these policies and analyze these policies by applying the principle of the ban on the over-restriction. Finally, we propose the direction and requirements of our national domestic encryption control policy that maintains the balance of peoples' constitutional rights and investigatory powers.