Security measures for Smart Devices through Cryptography Using Cellular Automaton

Present Embedded industry is emphasising more on Smart devices and they have gained much importance in daily life. The devices includes communication, Bio-Medical, image processing, Power, etc. While using smart devices (iButton Technology) data acquisition and user authentication has to be done.Various security concepts are developed to suite these requirement. One such security measure is using cryptography. Cryptography has gained much importance in the recent past due to the advancement in the technology for securing information. Visual Cryptography is such a cryptographic technique through which users hide information securely based on key authentication. This paper examines a new approach in visual cryptography using pextral coding algorithm in the framework of cellular automata. Primarily a 3 x 3 matrix pextral icon is considered. A 2D pextral icon is a convex polygon formed of pixels in a nine neighbourhood enclosing the central pixel. This central pixel is similar to a pixel considered for an image in Cryptography. Dropping one, two or three pixels in the given matrix forms 16 convex polygons. Out of these 16 polygons, few will have mirror symmetry. Two such mirror symmetry polygons were considered and the central pixel of these polygons will form the image pixel. An algorithm is developed to generate two signatures on an ASCII image. Combining the two signatures will reconstruct the original image. Results show that no loss of information and improved security. Keywords— Visual Cryptography, Authentication, Key, Pextral Coding, ASCII Image.