Essay Example on Visual cryptography plays a very crucial role for security of image based Secret

Visual Cryptography based Gray Share Generation Department of Computer Science Asst Professor Dept of Computer Science Institute of Engineering Institute of Engineering And Technology Kalady And Technology Kalady Abstract Visual cryptography plays a very crucial role for security of image based secret Visual cryptography encrypts the image in to shares and in decryption process all shares are stacked together to reveal the secret image This paper proposing a new scheme for color share generation In this scheme R G and B component is extracted from color image then apply gray share generation algorithm on R component and make n number of R gray shares then all shares are combine with B and G component to make color shares At decryption side B and G component is extracted from all shares and then combine all r gray share to make r component and after that all R G and B is combined to revealed the secret image Decrypted secret image has same size as original secret image Keywords Visual cryptography color image pixel expansion secret image hierarchical visual cryptography share I INTRODUCTION Data security is very important because most of our data is travelled over internet Many techniques have been proposed and developed for security of our data Secret data will be in the form of text image audio video etc Visual cryptography plays a important role for image security In this technique image is encrypted in to number of shares and at decryption side all or some of the shares are overlapped with each other to reveal the secret image 

We apply visual cryptography to encrypt color image instead of grayscale image or binary image In this paper color image is taken as an input to the system then we extract the R G and B component from color image After extraction phase gray share generation algorithms is applied on only R component and generate n number of R gray shares In next step we combine B and G component with all generated R gray shares to make color shares In decryption process we extract the B and G component from all shares to make R gray shares then all R gray shares goes to gray share generation algorithm and generates R component After this step R component is combine with B and G component to reveal the original secret image Here we apply gray share generation algorithm on R component and generates the shares and then combine with B and G components to make color shares so the security of secret image is increased by many fold II METHODOLOGY This paper proposed a new scheme for color share generation using visual cryptography Fig 1 shows color share generation flow In this flow color image is taken as input to the system then we decompose the R G and B component After this we have applied gray share generation algorithm on R component and generate n number of R gray shares where n 2 4 8 The generated R gray shares are combined with B and G component to make color share Fig 1 shows the encryption process Fig 2 shows gray share generation algorithm In this algorithm first take empty mask which has same size as R component and fill up the empty mask with zeros 

Then apply systematic randomization with key and generation final key mask In this equation n is the key value which is already delivered to transmitter and receiver side Based on the result of equation raw and column value is filled up by 0 and 1 by this way final key mask is generated X 1 2n2 Now the final key mask is XORed with R component and makes R gray shares After this step R gray shares are combined with B and G component to make color share Fig 3 shows color share combination flow In this flow B and G component is extracted from all color shares Then all R gray shares are fed as input to the gray share generation algorithm At this stage all r gray shares and final key mask is XORed with each other to make R component After this step R component is combine with B and G component to reveal the original color image III CONCLUSION This paper proposed a new color share generation scheme using visual cryptography In this scheme color image is encrypted in to n number of shares Here gray share generation algorithm is applied on R component and then n number of R gray shares are generated then all shares are combined with B and G component to make color share so the generated shares are highly secured The revealed secret image has same sizes original image and visual quality is also maintained IV REFERENCES 1 InKoo Kang Gonzalo R Arce and Heung Kyu Lee color extended visual cryptography using error diffusion IEEE 2009 2 Xiao Yi Liu Ming Song Chen and Ya Li Zhang A New Color Visual Cryptography Scheme with Perfect Contrast International Conference on Communications and Networking in China IEEE 2013 3 Shubhra Dixit Deepak Kumar Jain and Ankita Saxena An Approach for Secret Sharing Using Randomised Visual Secret Sharing IEEE 2014 4 J Ramya B Parvathavarthini An Extensive Review on Visual Cryptography Schemes IEEE 2014