Visual cryptography

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

Visual Cryptography

Abstract: In this paper, we propose a Visual Cryptographic system which can be used to hide the original image information from an intruder or an unwanted user. The images can be in any standard format. The encrypted image is sent to the destination through the network and then the image is decrypted. We have used Symmetric-key cryptography.

Human Encryptable Visual Cryptography

Abstract: We present a system to enable easy human encryption of visual cryptographic messages, consisting of pre-cut templates for use with a one-time pad. This allows for quick, manual creation of secret messages in the field. We describe a workshop that introduces students to the concept of visual encryption, then continues to allow students to generate their own secret messages. Introduction Visual cryptography is a method of hiding messages or images in a two-dimensional image that, by itself, is indistinguishable from random noise such that the message is decryptable visually by overlaying a key. The basic method was introduced by Naor and Shamir in 1994 [1]. This cryptographic method is generally easy for a human to decrypt, but is tedious, if not impossible, to encrypt without using a computer. Many more complex variations have since been explored, but all have a strong dependence on computers to easily create the encrypted message. E orts have been made to increase the ease of decryption of complicated visual cryptography messages involving many sheets [4], but the initial encryption method remains dependent on computers and printers. We introduce a system that enables rapid human encryption of visual cryptographic messages. In the field, this system would be used to quickly encrypt a message, after which the encryption tools and original message could be destroyed. The encrypted message could then be decrypted using a one-time pad already in the possession of its recipient. We then incorporate this system into a workshop that introduces students to the math and theory behind visual encryption, then allows them to generate their own secret messages by hand. Encryption Method The basic encryption remains the same as that originally described by Naor and Shamir [1]. The original image is a black-and-white m ⇥ n grid of pixels. The encrypted message and the key are each a 2m ⇥ 2n black-and-white image. They consist of 2⇥2 blocks, and each block has one diagonal black and one diagonal white, as in Figure 1. In the key, each block is chosen independently at random. For each original white pixel, the encrypted image contains the same block as the key. For each original black pixel, the encrypted image consists of the opposite block as the key. At least one of the key and the encrypted image is printed on a transparent sheet. When the sheets are overlaid, original black pixels look like a 2⇥ 2 black block, original white pixels are a half-white, half-black 2 ⇥ 2 block, and the secret image is visible. This is, in e ect, just a one-time pad [3]. By itself, each block of the key is just a left-diagonal or a right-diagonal, independently at random. Similarly, by itself, the key has exactly the same property – each block has an equal chance of being a left-diagonal or a right-diagonal, regardless of what the secret message contains. Bridges 2018 Conference Proceedings

Image Based Authentication fPhishing

Abstract: With the advent of internet, various online attacks have been increased and among them the most popular attack is phishing. Phishing is an attempt by an individual or a group to get personal confidential information such as passwords, credit card information from unsuspecting victims for identity theft, financial gain and other fraudulent activities. Fake websites which appear very similar to the original ones are being hosted to achieve this. In this paper we have proposed a new approach named as an "Image based authentication using Visual Cryptography" to solve the problem of phishing. The use of visual cryptography is explored to preserve the privacy of an image by decomposing the original image into two shares (one with user and one with server) such that the original image can be revealed only when both are simultaneously available; the individual sheet images do not reveal the identity of the original image. Using this website cross verifies its identity and proves that it is a genuine website before the end users. The emphasis of the project is to prevent the user from visiting a phishing website. The project aims at achievement of security of user and saving its confidential information from theft.

An Efficient Technique of Parallel Share Generation and Reconstruction for Medical Images

Abstract: The Healthcare Institutions are generates large amount of data now a days. Data like medical images, videos.so that institutions will uses cloud storage i.e third party server to store that large data. Storing data like Images or Videos securely in the third party servers is big challenge. In this paper, we proposed the system that will solve this security issue. This system provide security and privacy to the medical images by using (2,2) visual cryptographic techniques with Parallel processing. To ensure Confidentiality and authentication of data. This paper shows that our solution enhances data security by dividing the secret image into several shares which are parallelly encrypted in MATLAB so that encryption time of the images is reduced. In which shares are generated on two cores we can called as 2 workers and also on 4 workers parallelly. Analysis shows the time difference between 2 and 4 workers(cores) to generate shares. The main objective of this paper is to apply visual cryptography on medical images to provide authentication and to provide client side encryption by applying parallel processing for confidentiality of medical images and to reduce encryption time.

A secured approach for sharing critical data on halftone image Using advance visual cryptography

Abstract: Visual cryptography is a secret sharing scheme which uses images divided as shares such that, when the shares are created, a hidden secret image is attached. In extended visual cryptography, the share images are developed that contain meaningful cover images. For processing halftone images that improves the quality of the share images and the recovered secret image in an extended visual cryptography scheme for which the size of the share images and the released image is the same as for the original halftone secret image. The remaining scheme maintains the perfect security of the original extended visual cryptography approach. Keyword: Visual cryptography, Pixel Expansion, halftone image, Share, Secret image.