1,876 research outputs found

    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

    Survey on Biometric Image Sharing Using Cryptography and Diverse Image Media

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    Visual Secret Sharing Scheme is used to transmitting or delivering the secret images over the network. The VSS scheme has a major drawback that is it suffers from high transmission risk because the shares are like noise. As the shares are like noise that causes the attackers attention. In this paper we are using a natural-image based visual secret sharing (NVSS) scheme to reduce the transmission risk problem that occurs in VSS scheme. The NVSS scheme uses the natural images such as paintings, photographs etc as digital shares. As we are using the natural shares instead of noise like shares which reduces the transmission risk to certain limit. This scheme also uses the different media to transmit the shares

    An Application of Haar Wavelet Decomposition in Video Frames Preservation in Association with Visual Cryptography

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    Visual cryptography is one of the techniques used to encode the video by separating the original video. The proposed Visual cryptography gives the show to the users how encryption and decryption can be done to the video. Waveletchange are to provide characteristic of multiple declarationand worldwide decomposition that are the important features for thevideo compression application. The privacy and security becomes the most significant issues since the multimedia is transmitted openly over the network. A new adapted Haar Wavelet is used to encrypt the full video in an capable protected manner, after encryption the frame will decomposes and audio send final uncompressed video

    Visual Cryptography in Biometrics Passport

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    Every human being is unique in their nature such as traits and physical symptoms so computer science is using the biometric f or perfect identification within large database. Visual cryptography scheme is a cryptographic technique, which allows visual information e.g. printed text, handwritten notes, and picture to be encrypted in such a way that the decryption can be performed by the human visual system, without the aid of computers. Biometric passport is a smart card technology product created by use of biometric data and computer chip f or authenticate identification of citizen of particular country. Current passport has certain shortcoming. In the is method it is proposed to convert scan images of retina, fingerprint and face in secret image and meaningful shares by use of visual cryptography. In this method wi th use of Visual Cryptography three biometrics i.e . retina image, fingerprint image and fa ce image encrypted in two meaningful shares when these two share stacking on one another fingerprint image revealed and that can be verified with on the spot live fingerprint image for perfect identification accuracy

    Image Security using Visual Cryptography

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    Informations are being transferred through open channels and the security of those informations has been prime concerns. Apart from many conventional cryptographic schemes, visual cryptographic techniques have also been in use for data and information security. Visual cryptography is a secret sharing scheme as it breaks an original image into image shares such that, when the shares are stacked on one another, a hidden secret image is revealed. The Visual Cryptography Scheme is a secure method that encrypts a secret document or image by breaking it into image shares. A unique property of Visual Cryptography Scheme is that one can visually decode the secret image by superimposing shares without computation. Even to make the visual cryptography image shares more secure, public key encryption scheme is applied. Public key encryption technique makes image shares so secure that it becomes very hard for a third party to decode the secret image information without having required data that is a private key
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