Questions tagged [visual-cryptography]
Encrypting images so that they can be decrypted without using a computer, e.g. by superimposing two random-looking images.
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1answer
87 views
Security of (2,2) Shamir's visual secret sharing scheme : How are the 2 shares random?
From the Visual Cryptography by Shamir and Noar.
Let us take the pixel expansion as 2. Therefore, each pixel will be represented by 2 pixels (also called as subpixels) in a share. Since this is a (2,...
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1answer
1k views
Extracting the hidden text off an image embedded with steganography
Is it possible for me to extract the hidden text off a stego-image without using the same application that the hidden text was hidden with.
I used 5 applications that do steganography such as, ...
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1answer
94 views
Number of possible access structure with $n$ person
I want to count number of possible access structures in closed form(if possible) as a variable of $n$,the number of share holder. I have tried in several ways. Still no good progress. It is very hard ...
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2answers
177 views
Apply visual cryptography to a video stream?
I read that there are different ways to apply visual cryptography. One is to generate two images that when overlapped provide the original image. The main issue of using this approach with a video is ...
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1answer
372 views
Need of Image Encryption [closed]
Question is simple yet confusing, why there is the need for image encryption. How text encryption is different from image encryption if using same technique like AES, DES, Chaotic algorithm. If the ...
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0answers
179 views
Algorithms of steganography [closed]
Recently I'm working on steganography and I want to know that what are the main steganography algorithms and how they work.
I'll be happy if you help me.
thanks.
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3answers
3k views
Is there a cipher related to colors and letters?
I was just wondering if a cipher existed where a number of symbols were colored with different colors forming a cipher?
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1answer
477 views
Is my high school cryptography/steganography science fair project practical?
I'm a 12th grade student interested in a science project in cryptography and steganography for my school's science fair. I chose this path of computer science partly because my coding skills are weak (...
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2answers
624 views
Can a QR code be scanned if split using visual cryptography?
I'm trying to get a python script to work such a way that it takes a QR code (a jpeg or a png) splits the jpeg into two images as shown here
https://github.com/LessonStudio/VisualCryptography
I'm not ...
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0answers
14 views
Why the light contrast of a set $\mathcal{E}$ of VCRG produced by an encryption scheme for a binary image B is defined as follows
In the paper “Image encryption by multiple random grids”, Shyong Jian Shyu, 42(7):1582-1596,· July 2009, the light contrast of a set $\mathcal{E}$ of VCRG produced by an
encryption scheme for a binary ...
3
votes
1answer
93 views
The role of the dealer in visual cryptography
In visual cryptography schemes (VCS), there is special person called dealer. The dealer sets up the system, and the only one who knows about secret image. After encryption, the dealer distributes the ...
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0answers
151 views
Can you explain “k out of n” from the VCS paper by Naor and Shamir
I am new to visual cryptography. I’ve just read the paper “Visual Cryptography” by Moni Naor and Adi Shamir and I'm stuck on the chapter about the “$k$ out of $n$” construction. I am aware that, on ...
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1answer
91 views
Explanation of vector in Visual Cryptography
I'm starting to study about visual cryptography, but I am stuck with the following problem.
On paper "Visual Cryptography" by Moni Naor and Adi Shamir, on page 6. How to read/what is the meaning of
$...
5
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1answer
444 views
How can you produce visual cryptography?
I would like to be able to "code" images such as the one seen here on Wikipedia.
Is this generally produced with software, or does this require complex programming? Ideally, I would love to be able ...
4
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0answers
228 views
Explanation of part of a visual cryptography algorithm
I have been working on a project involving visual cryptography and I am stuck with the following problem.
My question is related to this paper, AN IMPROVED VISUAL CRYPTOGRAPHY SCHEME FOR SECRET ...
4
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2answers
428 views
Reusing message in One Time Pad
One of the main rules of the OTP is, that a key should never ever be reused.
But if we use some commutative operation (XOR for example) for generating the cipher text, then I don't see any difference ...
