Abstrakt

A Modified Approach for Symmetric Key Cryptography Using Circles

Deepti Rana , Shivani Saluja

Cryptography is the science or art of transforming an intelligible message(plaintext) into one that is unintelligible(cipher text) and then transforming the message back to its original form. . Symmetric key Cryptography is a cryptographic approach where the sender and receiver of a message share a single, common key that is used to encrypt and decrypt the message Geometry based cryptography is a new and emerging approach in the field of cryptography. It uses geometric shapes such as circles, ellipses etc and perform geometric transformations on these figures to produce cipher text. The presented work focuses on the Symmetric key Cryptography technique, using the concepts of Cartesian coordinate geometry and circle generation. Chakra algorithm, for symmetric key cryptography, is used as the basis for this work with some modifications in it for better results. Chakra is a Sanskrit term which means a circle or a disc. It plays a key role in encryption of data. Data is grouped into circles and each circle holds a portion of data. An improved geometric cryptographic algorithm is developed, that considers data into a 2- dimensional data grid, generate circles on the grid and apply some geometric transformations over data. This encryption technique adapts hybrid geometric transformations,(i.e., translation followed by scaling ) of the circumference points of every circle by some scaling factors(S,Sy) and translation factors(Tx,Ty). The proposed algorithm is an improvement in the basic Chakra algorithm in terms of accuracy.