416 research outputs found

    Development of Visual Cryptography Technique for Authentication Using Facial Images

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    Security in the real world is an important issue to be taken care and to be encountered with various aspects and preventive measures. In the present era, whole major security concerns is the protection of this multimedia web is coming closer from text data to multimedia data, one of the data. Image, which covers the highest percentage of the multimedia data, its protection is very important. These might include Military Secrets, Commercial Secrets and Information of individuals. This can be achieved by visual Cryptography. It is one kind of image encryption. Incurrent technology, most of visual cryptography areembedded a secret using multiple shares. Visual is secret sharing technique used in visual cryptography which divides the secret image into multiple shares and by superimposing those shares the original secret image is going to be revealed, but it create a threat when an intruder get shares with which the image is going to be decrypted easily. However in these project work, an extremely useful bitwise operation is perform on every pixel with the help of key. The key is provided by new concept of sterilization algorithm. Initially Red, Green and Blue channels get separated from image and are going to be encrypted on multiple levels using multiple shares, convert an image into unreadable format and by combining all the shares in proper sequence the original secret image revealed

    Secure (n, n + 1)-Multi Secret Image Sharing Scheme Using Additive Modulo

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    AbstractMulti Secret Image Sharing (MSIS) scheme is a protected method to transmit more than one secret images over a communication channel. Conventionally, only single secret image is shared over a channel at a time. But as technology grew up, there arises a need for sharing more than one secret image. An (n, n)-MSIS scheme is used to encrypt n secret images into n meaningless noisy images that are stored over different servers. To recover n secret images all n noise images are required. At earlier time, the main problem with secret sharing schemes was that one can partially figure out secret images by getting access of n – 1 or fewer noisy images. Due to this, there arises a need of secure MSIS scheme so that by using less than n noisy images no information can be retrieved. In this paper, we propose secure (n, n + 1)-MSIS scheme using additive modulo operation for grayscale and colored images. The experimental results show that the proposed scheme is highly secured and altering of noisy images will not reveal any partial information about secret images. The proposed (n, n + 1)-MSIS scheme outperforms the existing MSIS schemes in terms of security

    On Real-valued Visual Cryptographic Basis Matrices

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    Visual cryptography (VC) encodes an image into noise-like shares, which can be stacked to reveal a reduced quality version of the original. The problem with encrypting colour images is that they must undergo heavy pre-processing to reduce them to binary, entailing significant quality loss. This paper proposes VC that works directly on intermediate grayscale values per colour channel and demonstrates real-valued basis matrices for this purpose. The resulting stacked shares produce a clearer reconstruction than in binary VC, and to the best of the authors’ knowledge, is the first method posing no restrictions on colour values while maintaining the ability to decrypt with human vision. Grayscale and colour images of differing entropies are encrypted using fuzzy OR and XOR, and their PSNR and structural similarities are compared with binary VC to demonstrate improved quality. It is compared with previous research and its advantages highlighted, notably in high quality reconstructions with minimal processing

    (N,N) Share Generation using Key Share approach for RGB image in VCS

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    Visual Cryptography is a secure and unique image encryption technique which protects image based secret. In visual cryptography image is encrypted into shares and in decryption process all or some of shares are super imposed with each other to decrypt the original secret image. In this technique no complex computation is needed for decryption of secret image which is the best advantage of Visual Cryptography Scheme. In this report various types of visual cryptographic techniques are discussed from previous research area. In this proposed system (N, N) VCS is used for encryption. It takes color image as an input and extracts in R, G and B components. After that it generates Key-Mask using Key-Mask generation algorithm which XOR-ed with R, G and B components and gives the key shares. Further XOR operation of these key shares with key mask generates the color shares. In decryption process image is recovered by XOR operation between key mask and color shares. It has a better security features compared to previous one

    A novel quality assessment for visual secret sharing schemes

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    To evaluate the visual quality in visual secret sharing schemes, most of the existing metrics fail to generate fair and uniform quality scores for tested reconstructed images. We propose a new approach to measure the visual quality of the reconstructed image for visual secret sharing schemes. We developed an object detection method in the context of secret sharing, detecting outstanding local features and global object contour. The quality metric is constructed based on the object detection-weight map. The effectiveness of the proposed quality metric is demonstrated by a series of experiments. The experimental results show that our quality metric based on secret object detection outperforms existing metrics. Furthermore, it is straightforward to implement and can be applied to various applications such as performing the security test of the visual secret sharing process

    A Survey on Random Grid based Cryptography Schemes

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    A random grid based non-expanded Visual cryptography scheme used to generate meaningful as well as meaningless shares. First, analyze the distribution of pixels on the share image and stack image. A probability allocation method is introduced which is capable of producing the better visual quality in share image and stack image. With this method, it not only hide the secret image by using different cover images, but also visual quality of images is improve as needed. The important part is improvement of contrast of both secret and stack images to their theoretical maximum. This method is superior to past methods for visual secret sharing

    Cellular Automata Based Image Authentication Scheme Using Extended Visual Cryptography

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    Most of the Visual Cryptography based image authentication schemes hide the share and authentication data into cover images by using an additional data hiding process. This process increases the computational cost of the schemes. Pixel expansion, meaningless shares and use of codebook are other challenges in these schemes. To overcome these issues, an authentication scheme is proposed in which no embedding into the cover images is performed and meaningful authentication shares are created using the watermark and cover images. This makes the scheme completely imperceptible. The watermark can be retrieved just by superimposing these authentication shares, thus reducing the computational complexity at receiver's side. Cellular Automata is used to construct the master share that provides self-construction ability to the shares. The meaningful authentication shares help in enhancing the security of the scheme while size invariance saves transmission and storage cost. The scheme possesses the ability of tamper detection. Experimental results demonstrate the improved security and quality of the generated shares of the proposed scheme as compared to existing schemes
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