• International Journal of Computer Science & Network Security
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• v.22 no.6
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• pp.75-82
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• 2022

Medical data is one of the data that must be kept in safe containers, far from intrusion, viewing and modification. With the technological developments in hospital systems and the use of cloud computing, it has become necessary to save, encrypt and even hide data from the eyes of attackers. Medical data includes medical images, whether they are x-ray images of patients or others, or even documents that have been saved in the image format. In this review, we review the latest research and the latest tools and algorithms that are used to protect, encrypt and hide these images, and discuss the most important challenges facing these areas.

• International Journal of Computer Science & Network Security
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• v.24 no.2
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• pp.136-142
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• 2024

Haze is a very common phenomenon that degrades or reduces the visibility. It causes various problems where high quality images are required such as traffic and security monitoring. So haze removal from images receives great attention for clear vision. Due to its huge impact, significant advances have been achieved but the task yet remains a challenging one. Recently, different types of deep generative adversarial networks (GAN) are applied to suppress the noise and improve the dehazing performance. But it is unclear how these algorithms would perform on hazy images acquired "in the wild" and how we could gauge the progress in the field. This paper aims to bridge this gap. We present a comprehensive study and experimental evaluation on diverse GAN models in single image dehazing through benchmark datasets.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.1
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• pp.101-107
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• 2007

In this paper, we proposed an stable optical security system using interferometer and cascaded phase keys. For the encryption process, a BPCGH(binary phase computer generated hologram) that reconstructs the origial image is designed, using an iterative algorithm and the resulting hologram is regarded as the image to be encrypted. The BPCGH is encrypted through the exclusive-OR operation with the random generated phase key image. For the decryption process, we cascade the encrypted image and phase key image and interfere with reference wave. Then decrypted hologram image is transformed into phase information. Finally, the origianl image is recovered by an inverse Fourier transformation of the phase information. During this process, interference intensity is very sensitive to external vibrations. a stable interference pattern is obtained using self-pumped phase-conjugate minor made of the photorefractive material. In the proposed security system, without a random generated key image, the original image can not be recovered. And we recover another hologram pattern according to the key images, so can be used an authorized system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.759-766
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• 2017

In this paper, we preserve the transparency of digital contents by compressing and storing the medical image for a certain period so as to be safe and robust against various attacks of medical images. The proposed algorithm generates an encrypted image authentication code that extracts the feature value of the original image and combines it with the user's information. in order to extract hidden data, the authentication code is first decrypts the encrypted medical image and extracts the hidden data using the spatial characteristics of image. The proposed algorithm guarantees integrity when comparing extracted authentication code and newly generated authentication code for image authentication after directly inserting it into content itself through watermarking. We have proved various security of attack of image data and proved that the certification rate is improved to 98.4%.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.4
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• pp.153-166
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• 2008

According to the growth of the internet and the usage of software agents, the CAPTCHA that is a method for taking apart humans and computers has been widely deployed and used. As the results of many research activities, the CAPTCHA, which is spoken for a distorted image material including random text, has known to be easily breakable via artificial intelligence techniques. As one of alternatives for those text-based CAPTCHAs, methods using photos are concerned and various image-based CAPTCHAs are suggested. However, image-based CAPTCHAs still have some problems. In this paper, we discuss what are the problems in each image-based CAPTCHA and propose a new image-based CAPTCHA using image composition as the solution of those problems. Furthermore, for the secure operation of the CAPTCHA, we suggest a communication protocol that works without the virtual session and consider possible security and usability problems in the protocol.

• International Journal of Computer Science & Network Security
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• v.21 no.11
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• pp.17-22
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• 2021

Recently, image super-resolution techniques used in convolutional neural networks (CNN) have led to remarkable performance in the research area of digital image processing applications and computer vision tasks. Convolutional layers stacked on top of each other can design a more complex network architecture, but they also use more memory in terms of the number of parameters and introduce the vanishing gradient problem during training. Furthermore, earlier approaches of single image super-resolution used interpolation technique as a pre-processing stage to upscale the low-resolution image into HR image. The design of these approaches is simple, but not effective and insert the newer unwanted pixels (noises) in the reconstructed HR image. In this paper, authors are propose a novel single image super-resolution architecture based on synchronized depthwise separable convolution with Dense Skip Connection Block (DSCB). In addition, unlike existing SR methods that only rely on single path, but our proposed method used the synchronizes path for generating the SISR image. Extensive quantitative and qualitative experiments show that our method (SDCN) achieves promising improvements than other state-of-the-art methods.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.6
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• pp.1111-1123
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• 2023

In recent years, as generative models have developed, research that threatens them has also been actively conducted. We propose a new membership inference attack against text-to-image model. Existing membership inference attacks on Text-to-Image models produced a single image as captions of query images. On the other hand, this paper uses personalized embedding in query images through Textual Inversion. And we propose a membership inference attack that effectively generates multiple images as a method of generating Adversarial Prompt. In addition, the membership inference attack is tested for the first time on the Stable Diffusion model, which is attracting attention among the Text-to-Image models, and achieve an accuracy of up to 1.00.

• The Journal of the Korea Contents Association
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• v.2 no.3
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• pp.80-86
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• 2002

In this paper, we propose the new optical security technique using two phase holograms based on interferometer. The encoded random phase image does not have any information on the original image. Without Hewing the key mask, one cannot decode the encrypted image and regenerate the original image. And the use of two phase only images in the proposed security system leads to maximum optical efficiency (100% in theory). Also they cannot be detected by an intensity detector such as a CCD camera. Computer simulations and optical experiments show performance of the proposed methods.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1678-1680
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• 2002

Stereo matching technique is used in many practical fields like satellite image analysis and computer vision. In this paper, we suggest a method to extract a target object image from a complicated background. For example, human face image can be extracted from random background. This method can be applied to computer vision such as security system, dressing simulation by use of extracted human face, 3D modeling, and security system. Many researches about stereo matching have been performed. Conventional approaches can be categorized into area-based and feature-based method. In this paper, we start from area-based method and apply area tracking using scanning window. Coarse depth information is used for area merging process using area searching data. Finally, we produce a target object image.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.73-82
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• 2022

This paper shows the hiding process of unlimited secret text size in an image using three methods: the first method is the traditional method in steganography that based on the concealing the binary value of the text using the least significant bits method, the second method is a new method to hide the data in an image based on Exclusive OR process and the third one is a new method for hiding the binary data of the text into an image (that may be grayscale or RGB images) using Exclusive and Huffman Coding. The new methods shows the hiding process of unlimited text size (data) in an image. Peak Signal to Noise Ratio (PSNR) is applied in the research to simulate the results.