Secure high capacity tetris-based scheme for data hiding

Information hiding is a technique that conceals private information in a trustable carrier, making it imperceptible to unauthorised people. This technique has been used extensively for secure transmissions of multimedia, such as videos, animations, and images. This study proposes a novel Tetris-based data hiding scheme to flexibly hide more secret messages while ensuring message security. First, an LQ  × LQ square lattice Q is selected to determine the maximum embedding capacity, and then it is filled without gaps through rotating and sliding tetrominoes while making the shape of each tetromino different. Secondly, according to the decided Q, the reference matrix and corresponding look-up table are constructed and then used for secret messages embedding and extraction. In the authors approach, each pixel pair of the original image can be processed to conceal 4- or 6-bit secret messages. The experimental results show that their proposed Tetris-based scheme has excellent performance, exceeding the performance of some state-of-the-art schemes in both embedding capacity and visual quality. The proposed scheme also provides secure covert communication.