Image encryption using the rectangular Sudoku cipher

A new block cipher using the rectangular Sudoku matrix is presented in this paper. The proposed block cipher eliminates the size limitation of the standard Sudoku cipher and combines advantages of both the transform-based and chaos-based encryption methods. Our simulation results demonstrate that (1) the proposed cipher is robust and effective for all kind of images; (2) the encrypted image is very random-like and has a flat histogram; (3) the proposed cipher is highly sensitive to the encryption key and has an extremely large key space; and (4) the proposed cipher is applicable to other multimedia data.