Topic
Visual cryptography
About: Visual cryptography is a research topic. Over the lifetime, 1724 publications have been published within this topic receiving 25300 citations.
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TL;DR: By controlling the randomness of the sharing phase according to constraints from both SISSs, this work combines polynomial-based SISS (PSISS) and random-grid-based visual cryptography scheme (RGVCS) together, and proposes an ideal ( k 1, k 2 , n ) -threshold TiOSISS for multiple secrets.
7 citations
31 Oct 2012
TL;DR: This work tries to provide a general model for the watermarking schemes obtained from the combination with visual cryptography, and discusses some possible extensions of the combined approach taking into account different visual cryptographic schemes where multiple participants are involved and their possible applications in new scenarios.
Abstract: The proliferation of digital data, and their distribution over different kinds of communication channels are making the copyright protection a very important issue in the digital world. Watermarking techniques and visual cryptographic schemes have been recently used in different approaches for the copyright protection of digital images. Watermarking is generally used to embed "secret" information into an original image, with different purposes and different features, usually as a means to assess the ownership of the modified image. Visual cryptography refers to a way to decompose a secret image into shares and distribute them to a number of participants, so that only legitimate subsets of participants can reconstruct the original image by combining their shares.
The combination of both techniques can provide some important solutions for tampering verification and the resolution of disputes on the ownership of a given image, as provided by several proposals appeared in literature. In this work we try to provide a general model for the watermarking schemes obtained from the combination with visual cryptography. Furthermore we discuss some possible extensions of the combined approach taking into account different visual cryptographic schemes where multiple participants are involved and their possible applications in new scenarios.
7 citations
17 Dec 2008
TL;DR: A scheme to hide two watermarks in visual secret sharing of a gray level image that is embedded during secret image halftoning, and the other is hidden during the halftone image encryption.
Abstract: This paper proposes a scheme to hide two watermarks in visual secret sharing of a gray level image. One watermark is embedded during secret image halftoning, and the other is hidden during the halftone image encryption. A non-expansion visual secret sharing model is used to encrypt the halftone image. In watermark extraction, only Exclusive-OR operation is needed, and basic properties of conventional visual cryptography technique are still preserved. Experimental results show the effectiveness of our schemes.
7 citations
Patent•
05 Jan 2010
TL;DR: In some embodiments, techniques for voting and visual cryptography may include various enhancements as discussed by the authors, e.g., enhancements to the hardware, software, or hardware, such as voting hardware.
Abstract: In some embodiments, techniques for voting and visual cryptography may include various enhancements.
7 citations
18 Jul 2012
TL;DR: Compared with the literature schemes, the improved aspect ratio invariant visual cryptography scheme with optional size expansion can preserve the details well, especially for the thin lines in the secret image.
Abstract: Traditional visual cryptography scheme has a shortcoming of size expansion of the revealed image. Usually, the expansion ratio m is not a square integer, and results in the variant aspect ratio of the revealed image. The large size expansion is not convenient for storage and transmission. In this paper, an improved aspect ratio invariant visual cryptography scheme with optional size expansion is proposed. The details of the secret image have a priority to be preserved in the revealed image. Theoretically, the size expansion can be any value larger than 0. Compared with the literature schemes, our scheme can preserve the details well, especially for the thin lines in the secret image.
7 citations