Visual cryptography

Visual cryptography (VC) was introduced by Moni Naor and Adi Shamir at EUROCRYPT 1994.

Visual cryptography is a cryptographic technique which allows visual information (pictures, text, etc.) to be encrypted in such a way that decryption becomes a mechanical operation that may or may not require a computer.

It is used to encrypt written material (printed text, handwritten notes, pictures, etc) in a perfectly secure way.

OR- Visual Cryptography

Divide image into two parts

Separately, they are random noise

Combination reveals an image

k out of n sharing problem

For a set P of n participants, a secret image S is encoded into n shadow images called shares (shadows), where each participant in P receives one share.

The original image is visible if any k or more of them are stacked together, but totally invisible if fewer than k transparencies are stacked together.

k out of n example (k=3,n=4)

General k out of k Scheme

In k out of k, the image is visible only if all the shares are stacked together.

If any share in k is lost, and remaining shares are stacked together, it will not form the image.

Thus, in k out of k, all the shares are important

to construct the image.

2 out of 2 Scheme (2 subpixels)

X-OR Visual Cryptography

It is a type of cryptography technique in which we encode image in such a way that we get original image after decoding.It is not possible in normal cryptography technique.Decoding can be done by human visual system or directly with the help of computer

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Monika Agrawal

I am Monika Agrawal from Mathura. Currently, I'm enrolled in B.Tech ( 3rd year) Computer Engineering and Application. My strength is my attitude that I like to take challenges that I CAN do.I am self motivated person, self disciplined and a good team player as well as has a good ability to lead the team. I can adopt to any kind of environment. I am a good listener and quick learner. My weakness is I can not tolerate any leniency in work. My short term goal is I want a such a platform where I can grow my career along with the organisation growth. My Long term goal is I want to be one of the reason for the success of the organisation I am working for and I want to see that organisation as a bench mark to other organisations.