Topic
Visual cryptography
About: Visual cryptography is a research topic. Over the lifetime, 1724 publications have been published within this topic receiving 25300 citations.
Papers published on a yearly basis
Papers
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01 Jan 2016TL;DR: A quick look at the salient moments of visual cryptography's history, focusing on the main models, on open issues, on its applications and on some prospec-style models are given.
Abstract: Since its introduction, visual cryptography has received considerable attention within the cryptographic community. In this paper we give a quick look at the salient moments of its history, focusing on the main models, on open issues, on its applications and on some prospec-
5 citations
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TL;DR: A modified phase retrieval algorithm is proposed and a hierarchical visual cryptography scheme (HVCS) is presented that overcomes the problems that are mentioned and can share multiple secret images.
Abstract: Visual cryptography is generally based on the base matrix scheme or the random grid scheme. These schemes may cause some problems, such as the expansion of the shares and the recovered images and the distortion of the recovered images. In this paper, we propose a modified phase retrieval algorithm and present a hierarchical visual cryptography scheme (HVCS). The scheme overcomes the problems that are mentioned and can share multiple secret images. Considering the differences in the social division of labor, there is a hierarchy between the shared images in the proposed scheme, that is, the participants have different rights. Further, to make the proposed scheme more applicable to practical needs, we propose a generalized HVCS by modifying the phase retrieval algorithm again so that each level can have more than one participant. The effectiveness and feasibility of the proposed scheme are verified by theoretical analysis and numerical simulation.
5 citations
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17 Jun 2008TL;DR: This paper uses Hilbert curve and two queues to present a VC scheme with the following properties: each shadow image is as small as the input image S and contrast-optimal algorithms can be directly and easily applied to this scheme.
Abstract: Visual cryptography (VC) was introduced by Naor and Shamir. In general, a (k, n)-threshold scheme shares a given secret image S among n so-called shadow images. People can "view" the secret image by simply stacking any k of these n shadows (k < n is a threshold value). In most of the reported VC schemes, the size of each shadow is greater than that of S. This paper, we use Hilbert curve and two queues to present a VC scheme with the following properties: (1). Each shadow image is as small as the input image S. (2). Many gracious (k, n) contrast-optimal algorithms can be directly and easily applied to our scheme. (3) Image quality is competitive.
5 citations
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18 May 2005
TL;DR: The proposed scheme is promoted by the great advantage of visual cryptography as it is without complicated mathematical operations and will not destroy the protected image while making the colored digital watermark.
Abstract: Summary form only given. For a period of time, it was popular to use gray-level and black-and-white authentication logos for digital watermarking. With the changes of times, there are more and more digital watermarking techniques using colored logos for the index of its authentication. However, the algorithm must be more complicated for using colored logos to develop digital watermarking. It depends on a lot of complicated mathematical operations to embed the colored digital watermark. In this paper, an application of using visual cryptography technology on the making of colored digital watermarks is proposed. The proposed scheme is promoted by the great advantage of visual cryptography as it is without complicated mathematical operations. Using the human visual system, the secret can be distinguished. Our approaches not only keep the advantage of visual cryptography, but also will not destroy the protected image while making the colored digital watermark.
5 citations
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TL;DR: This work proposes a new technique in hiding the information that the encrypted shares are encrypted by inter-pixel exchanging using a secondary image and proposes the significance in use of hybrid halftoning in visual cryptography.
5 citations