6,373 research outputs found

    VISUAL CRYPTOGRAPHY FOR COLOR IMAGES

    Get PDF
    Visual cryptography is a secret sharing scheme for encrypting a secret image, it is a perfectly secure way that allows secret sharing without any cryptographic computation, which is termed as Visual Cryptography Scheme (VCS). In this paper secret image is divided into shares (printed on transparencies), and each share holds some information. At the receiver this shares are merged to obtain the secret information which is revealed without any complex computation. The proposed algorithm is for color host image, divided into three color planes Red, Green, Blue and merged with secret image which is binarized and divided into shares. The decoding requires aligning the result obtained by merging color host image and shares, so as to obtain the secret image

    Two-out-of-two color matching based visual cryptography schemes

    No full text
    International audienceVisual cryptography which consists in sharing a secret message between transparencies has been extended to color prints. In this paper, we propose a new visual cryptography scheme based on color matching. The stacked printed media reveal a uniformly colored message decoded by the human visual system. In contrast with the previous color visual cryptography schemes, the proposed one enables to share images without pixel expansion and to detect a forgery as the color of the message is kept secret. In order to correctly print the colors on the media and to increase the security of the scheme, we use spectral models developed for color reproduction describing printed colors from an optical point of view

    IMPLEMENTASI TEKNIK KRIPTOGRAFI VISUAL PADA CITRA KEABUAN DAN BERWARNA UNTUK OTENTIKASI PENGGUNA PADA TRANSAKSI ONLINE

    Get PDF
    Visual cryptography (VC) technique encodes an image into two or more shares that appear random in human eyes. In the decryption section, the pixels in the shared images are combined to obtain the information contained in the original image. This study applies visual cryptographic techniques to graysle and color images for user authentication in online transactions using the VC2,2 scheme. The server computer encodes the CAPTCHA image into two shared images that are sent to the user through different channels or applications. To authenticate himself, the user performs an XOR operation on both share images, identifies the information contained in the CAPTCHA and sends it to the server. In encryption test, histogram of the share image has a different pattern from the original image. The description test shows the decrypted image in this study visually has a better quality than the binary image has better quality than binary images

    The Visual Secret Sharing Scheme Based on the Rgb Color System

    Full text link
    The visual secret sharing (VSS) scheme is a method to maintain the confidentiality of a se-cret image by sharing it to some number participants. A (k, n) VSS divides the secret images into n parts, that are called shadows ; to recover the secret back, k shadows should be stacked. Some methods have been developed to implement VSS for color images. However, the methods are only suitable for images with limited number of colors. When more colors are used, the resulted stacked shadow image becomes unclear. Besides that, the size of the shadows becomes bigger as more colors are used. We develop a new method implementing the VSS using the RGB color system. Using our method, the problem related to the unclear stacked shadow image can be overcome
    • …
    corecore