  In this paper, a new approach to Spread Spectrum (SS) watermarking technique
is introduced. This problem is particularly interesting in the field of modern
multimedia applications like internet when copyright protection of digital
image is required. The approach exploits two-predecessor single attractor
(TPSA) cellular automata (CA) suitability to work as efficient authentication
function in wavelet based SS watermarking domain. The scheme is designed from
the analytical study of state transition behaviour of non-group CA and the
basic cryptography/encryption scheme is significantly different from the
conventional SS data hiding approaches. Experimental studies confirm that the
scheme is robust in terms of confidentiality, authentication, non-repudiation
and integrity. The transform domain blind watermarking technique offers better
visual & statistical imperceptibility and resiliency against different types of
intentional & unintentional image degradations. Interleaving and interference
cancellation methods are employed to improve the robustness performance
significantly compared to conventional matched filter detection.
