Development Of Mixed Chaotic Encryption Methods For Document Images

Abstract

The advancement in digital electronics and web based technology has led to document newlineimaging occupying prime importance and wide acceptance as the most reliable form of newlinepreserving and exchange of sensitive data and also required to comply with the Federal newlineInformation Processing Standards (FIPS) regulation of the United States of America. newlineCryptographic techniques provide security for sensitive document images against newlineauthenticity, confidentiality, non-repudiation and integrity when communicated over newlineunsecured channels. In this thesis new approaches for enciphering and deciphering of newlinedocument images applying multiple chaotic systems having different dimensions are newlineproposed. This research comprises of three different phases. The first phase is with the complete newlineencryption and decryption of document images using three different schemes. In the second phase, the document images are encrypted partially or selectively to newlinereduce the time required for encryption to synchronize the needs of the applications in newlinereal time The third phase involves the encryption and decryption of heterogeneous document newlineimages with different levels of security. The evaluation of the performance of the recommended encryption/decryption schemes newlineusing single and multi-dimensional chaotic maps are made against security level with newlinethe statistical and dynamical attacks, the encryption speed and robustness against the newlineloss of information and against the noise, accumulated in the channel. The results newlineensured the resistance of the system to both statistic and differential attacks, high speed newlineand robust both against loss of information and noise, in comparison to the existent newlineschemes for all document image types considered. The system is NIST compliant and newlinethereby ensures randomness of the pseudorandom sequences originated. The newlineapplication of these in the encryption and decryption system ensures more security and newlinespeed. The results ensure that the multiple chaotic systems with different dimensions newlineare more efficient than the single chaotic system with the same dimensions. newline