Bit Slicng based Visual Cryptography On Gray Scale ImageÂ

Data transmission through online is become mandatory in recent ages. No one can avoid data transmission over internet. But sensitivity of the data to be considered while transmits over internet. Internet is public medium where everyone has equal right to do their activities. Like in general public, internet also having malicious users and their main activity is deployment of attack. These attacks are of many types such as hacking, tampering and eavesdropping etc. Efficient data hiding techniques are required to with stand these attacks or to escape from these attacks. Visual Cryptography is one of such techniques to hide multimedia data in other multimedia data such as images, audio files or video files. In the proposed system secret image is partitioned or divided into shares based on the bits. These shares are then covered with given cover images then these covered shares are distributed to ‘n’ participants. To recover the secret all those participants are required. The proposed approach followed a novel method of bit slicing on gray scale images. So at the time of recover secret image cant’ be visible with same intensity or resolution as that of original image. For this purpose four secret keys are used. Simulation results shows that when compared to existing schemes , proposed approach can hide the image under cover images in efficient way as well as recovering of secret also lightweight and resilience to attacks

Overcoming Alignment Problem in Non-Identical Mathematical Support Visual Cryptography Schemes

An important problem in visual cryptography is the alignment problem. Although Liu, et al. have proposed a method for aligning the shares, there is still a problem with the non-identical mathematical support visual cryptography schemes. For overcoming this problem, the Three-Orthogonal-Point (3OP) method is proposed in this paper. Based on the experimental result it was proven that it can overcome the alignment problem, while the time complexity for aligning the shares is decreased significantly from O((m×A)2) to O(m×AI), for AI < A. The security is maintained, since an attacker cannot obtain any information related to the secret image

ESSVCS: an enriched secret sharing visual cryptography

Visual Cryptography (VC) is a powerful technique that combines the notions of perfect ciphers and secret sharing in cryptography with that of raster graphics. A binary image can be divided into shares that are able to be stacked together so as to approximately recover the original image. VC is a unique technique in the sense that the encrypted message can be decrypted directly by the Human Visual System (HVS). The distinguishing characteristic of VC is the ability of secret restoration without the use of computation. However because of restrictions of the HVS, pixel expansion and alignment problems, a VC scheme perhaps can only be applied to share a small size of secret image. In this paper, we present an Enriched Secret Sharing Visual Cryptography Scheme (ESSVCS) to let the VC shares carry more secrets, the technique is to use cypher output of private-key systems as the input random numbers of VC scheme, meanwhile the encryption key could be shared, the shared keys could be associated with the VC shares. After this operation, VC scheme and secret sharing scheme are merged with the private-key system. Under this design, we implement a (k; t; n)-VC scheme. Compared to those existing schemes, our scheme could greatly enhance the ability of current VC schemes and could cope with pretty rich secrets