Pandey, Binay KumarSingh, Chetana2019-02-012019-02-012018-08http://krishikosh.egranth.ac.in/handle/1/5810093224These days secured data storage and transmission have become an important issue in this digital world due to increased use of internet for communication purpose. Information security is becoming more important as the amount of sensitivity data being exchanged on the Internet increases. The service like confidentiality and data integrity are required to protect data against unauthorized usage and modification. In these years several image encryption methods are introduced by various researches to secure multimedia information while transmit via public networks. A novel Keyless Image encryption method based on chaotic map is suggested in this research work. Each component of image is encrypted by shuffling pixels and this shuffling is decided by the modified cat map. To transmit data whole image is convert into linear form then modulate the linear data using modulation technique OQPSK. The results confirm that the proposed method resist the statistical analysis. Also attains acceptable correlation coefficient value and has a robust performance against attacks. The simulation of the above algorithm is done on Matlab.ennullThesis