Visual cryptography

About: Visual cryptography is a research topic. Over the lifetime, 1724 publications have been published within this topic receiving 25300 citations.

Extended visual cryptography scheme with an artificial cocktail party effect

Abstract: Visual cryptography schemes have been introduced in 1994 by Naor and Shamir [9]. These kind of schemes have been also well described by C. Blundo, A. De Santis and D.R. Stinson in [3]. In this case, a secret image I may be encoded into n shadow images called the shares, and to give exactly one such shadow image to each member of a group P of n persons. Certain qualified subsets of participants can visually recover I, but other, forbidden sets of participants have no information on I. A visual recovery for a set X consists of photocopying the shares given to the participants and then stacking them. Shortly afterwards the discovery of visual cryptography schemes Droste gave a generalization of such schemes, and Ateniese et al, formalized the idea of Naor and Shamir of an extension of the model which conceals the very existence of the secret image. Ateniese et al have called this formalization, Extended Visual Cryptography [5, 7,10]. In order to encode and hide a given set I1, I2, . . . , Ik of gray-level images, in this paper, we propose an Extended Visual Cryptography Scheme for which the decoding process simulates a cocktail party effect. (10 pages)

The Improvement of Flip (2,2) Visual Cryptography Images Using Two Key Images

Abstract: The Flip (2, 2) Visual Cryptography (FVC) is one of the techniques used to encrypt the two secret images into two dual purpose transparencies. The two transparencies can be sent to the objective person. The first secret images can be obtained by stacking the two transparencies and the second secret images can be obtained by stacking the one transparency with the flipping other transparency. Unfortunately, the result decryption processes still have noise and the quality of decrypted secret image is not as same as original secret image. This article proposed the new algorithm to improve the quality of decryption secret image. In this process, the two secret images from decryption process were compared with the two original secret images. The different values of each pixel, which was counted from subtraction of decryption image and original secret images, will be inserted to the two key images. The experimental results of this improvement have a good similarity. The noise in decryption process can be eliminated so the two secret images reconstruction similar to the original secret images.

Visual Cryptographic Technique forEnhancing the Security of Image Transaction

Abstract: As the growth in the technology increases maintaining the security of visual information during its transaction has to be increased. Rapid growth in the techniques for doing so is also increasing. Internet has become most commonly used media for communication and hence text, voice, video, Images and many more are transmitted through Internet. These might include Military Secrets, Commercial Secrets and Information of individuals and therefore it has to be transmitted by safer means with enhanced security. In the process of Visual Cryptography a secret image is encrypted into shares which refuse to divulge information about the original secret image. In this paper, Chaotic Pseudo – Random Number generation, Zigzag Scan Pattern Method, Method to reduce the degradation of the resultant image is proposed by an extension from gray to colour image. Pixel Index Method is discussed to improve the security for images. An integration of this technique of Visual Cryptography with (n, k, p) gray image is also proposed.

Securing software defined network transactions using visual cryptography in steganography

Abstract: In the Software-Defined Network many transactions of data have been made, the need for securing this data very imperative. One of the most successful ways to secure data is by adding layers of both cryptography and steganography. In past years, many attempts to achieve this approach is done, but in this paper, a discussion made on how this approach works on Software-Defined Network, by first hiding secret messages inside the randomly generated image using LSB algorithm and then encrypting it using simple Visual Cryptography which based on creating two noisy images concluded from the original and only can be restored by stacking these images together. At the end of this research, results showed that two layers of security can be more secure than the one layer, this way the attacker can be obscured about the data hidden. The reason behind the implementation of this approach in SDN because of its importance since it’s been used in many organizations and they need the data to be secured. Another problem that occurred in this system, is the latency to transfer the data from one node to another since this approach uses multimedia as a payload to transfer the data, a compression layer must be added, to decrease the amount of data sent through the network. After all this work, the data is now secured by applying two layers of security and faster to transfer hence this data is reduced by compression and simple visual cryptography is used and the BZIP2 compression technique to reduce processing of data.

Multi-secret Images Sharing Based on Matrix Multiplication

Abstract: Based on matrix multiplication secret sharing method, a multi-secret images sharing scheme is presented. In our scheme, participants only need to pool their pseudo-shadow instead of disclosing his secret share when recovering secret images. That is to say, each participant can share many secret images with others by holding only one secret share. Unlike other known image sharing scheme, it doesn’t generating shadow images which are difficult to manage and identify. Integrating the above advantages, this scheme is a practical and effective multi-secret image sharing scheme.