Visual Cryptography using KN Sharing Algorithm for Colour Images

s-To verify identity of person his /her physical or behavioural characteristics can be use,this strategy is called as Biometrics. Preservation of privacy of digital biometric data such as iris,face images etc. which stored in central database becomes more essential. This paper introduced the new visual cryptographic technique that allows encryption of visual information such that decryption can perform using human visual system hence cryptography computation does not required any extra hardware and software. In visual cryptography secrete image is encrypted into number of shares which independently can not reveal information about original image. For getting information about original image all sheets must be available simultaneously.

Visual Cryptography is a special encryption technique that encrypts the secret image into n number of shares to hide information in images in such a way that it can be decrypted by the human visual system. It is imperceptible to reveal the secret information unless a certain number of shares (k) or more are superimposed. Simple visual cryptography is very insecure. Variable length key based visual cryptography for color image uses a variable length Symmetric Key based Visual Cryptographic Scheme for color images where a secret key is used to encrypt the image and division of the encrypted image is done using Random Number. Unless the secret key, the original image will not be decrypted. Here secret key ensures the security of image. This paper describes the overall process of above scheme. Encryption process encrypts the Original Image using variable length Symmetric Key, gives encrypted image. Share generation process divides the encrypted image into n number of shares using random number. Decryption process stacks k number of shares out of n to reconstruct encrypted image and uses the same key for decryption.

International Journal of Information Systems and Computer Sciences, 2019

Cryptography is the main pillars of information security. By the arrival of internet, its usage and usefulness has exploded. Cryptography means storing and transmitting data in a form that only targeted people can read and process. It is also an effective way of protecting sensitive data that is stored on media devices or transmitted over an unsecured network communication channel by encrypting it into an unreadable format. Visual cryptography is a cryptographic technique used to encodes a black and white secret image into n shadow image called shares and these shares are distributed among n participants and only qualified subset of participants can visually recover the secret image. DCT is used in the proposed system. It has two encryption methods: lossy encryption and lossless encryption. Lossless encryption is more appropriate because it preserves every single detail in the image.It reduces the transmission risk problem and the quality of image is retained.

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The Visual cryptography scheme (VCS) is a secure method that encrypts a secret image by breaking it into shares. A distinctive property of VCS is that one can visually decode the secret image by superimposing shares without computation. The project ...

Visual Cryptography is a special type of encryption technique to obscure image-based secret information which can be decrypted by Human Visual System (HVS). It is a kind of secret-sharing scheme that encrypts the secret image into n number of shares. It is imperceptible to reveal the secret information unless a certain number of shares(k) or more are superimposed. As the decryption process is done by human visual system, secret information can be retrieved by anyone if the person gets at least k number of shares. For this, simple visual cryptography is very insecure.

Journal of Software Engineering and Applications, 2017

Visual cryptography (VC) is one of the best techniques used to secure information. It uses the human vision to decrypt the encrypted images without any cryptographic computations. The basic concept of visual cryptography is splitting the secret image into shares such that when the shares are stacked, the secret image is revealed. In this paper we proposed a method that is based on the concept of visual cryptography for color images and without any pixel expansion which requires less space. The proposed method is used to encrypt halftone color images by generating two shares, random and key shares which are the same size as the secret color image. The two shares are generated based on a private key. At the receiving side, the secret color image is revealed by stacking the two shares and exploiting the human vision system. In this paper, we produce an enhanced form of the proposed method by modifying the encryption technique used to generate the random and the key shares. Experimental results have shown that the proposed and the enhanced methods suggest an efficient way to encrypt a secret color image with better level of security, less storage space, less time of computation and with a better value of PSNR.

IRJET, 2021

Visual cryptography is a secret sharing technique for securing visual contexts like images or texts by encoding into multiple number of shares. In decryption process, one can decrypt the secret image (SI) by stacking the shares without any additional computations. Color visual cryptography (CVC) encodes a color secret image (SI) into several shares in which each color pixels are separately handled using RGB or CMY models. In this paper we proposed CVC technique for secret color images encoding schemes with multiple encryption algorithm to make the secret image highly secured. In this method, a color secret image is encrypted by extracting R, G, B component from the original secret image and halves of each of them into two separate matrices. Each of these matrices are then XORed with a randomly generated key matrices (Ki) to generate six different shares for each of the three color planes. By using Hou's scheme, share 1 and share 2 are then constructed by stacking the three first level shares and three second level shares of each color components respectively. The generated two shares are further encrypted by hybrid security algorithm called AES and Blowfish. On the recipient side, color SI is retrieved form these shares with the equivalent quality as that of original image by performing all the operations that we accomplished in the encryption processes in reverse order. The proposed method is then evaluated by using performance measures such as PSNR and SSIM. The result obtained by these two evaluation parameters show that the reconstructed image retain the quality of the original image. Therefore the proposed method is excellent for hiding secrets in the form color images confidently compared to the existing VCS schemes.

International Journal of Computer Applications, 2011

Visual cryptography is a special type of encryption technique where visual information (Image, Text etc) gets encrypted in such a way that decryption can be performed by Human Visual System with a computation free decryption process. The beauty of the visual secret sharing scheme is in its decryption process where without any complex cryptographic computation encrypted data is decrypted using Human Visual System (HVS). But the encryption technique needs cryptographic computation to divide the image into a number of parts let n such that at least a group of k shares out of n shares reveals the secret information, less of it will reveal no information. In this paper we have discussed a technique called random sequence which needs very less computation for k-n secret sharing.

Visual Cryptography is an efficient encryption method to conceal information in images so that it very well may be decrypted by the human visual framework. The benefit of the visual secret sharing can be achieved by utilizing its decryption procedure where with no complex cryptographic calculation encoded secret information is decoded by Human Visual System (HVS). Be that as it may, the encryption strategy needs cryptographic calculation to partition the image into various parts for sharing (let n). k-n secret sharing plan is an exceptional sort of Visual Cryptographic procedure where gathering of k shares is required out of n shares to uncover the secret information, less than k shares will results in no information which leads to the safety of secret information. In our paper we have proposed a k-n secret sharing system for color image. We have taken an image which is to be shared secretly. This image is encoded utilizing a key given by the sender on which recipient also agrees. Further, the encrypted image is partitioned into N divisions shares utilizing K N Secret Sharing Algorithm. These N shares can be disseminated at the same time, the end user needs just K of these divisions to produce the original image. After the original image is produced it is still encoded. The key which is utilized to encrypt the image initially is presently required again to decrypt it, along these lines giving an extra dimension of security. International Research Journal of Engineering and Technology (IRJET) e© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 935