There has been a considerable debate on the applicability of conventional encryption techniques for protecting images. Chaos based encryption systems are preferred for digital image encryption for a long time now. For a reliable encryption method any alteration in image content or the key must be reflected in the cipher image. The present work demonstrates a highly secure and reliable encryption of the color images using chaotic dynamical system augmented by pixel shuffling based on 3-D matrix, and further subjected to a diffusion process. This proposed model yields an average NPCR and UACI values of ≥ 99.6% and ≥ 33.34% respectively and nearly no correlation among neighbouring pixels which indicates a higher immunity towards attacks. The proposed model ensures information integrity during transmission which was further validated with a series of simulations e.g. entropy, noise addition, tampering and compression. Further, statistical analysis was also carried out using histogram analysis for different types of attacks. The model shows its prominence in scenarios where the transmission of image based sensitive information is critical.