الملخص

The present research was aimed to design and implement an algorithm that combines cryptography and steganography to achieve a higher level of security. The algorithm hid encrypted text into color images in a scattered manner based on randomly generated numbers. The rules of cellular automata were used to encrypt the secret text and generate random numbers. Each character of a secret text was treated as a cellular automaton and the rule 153 was used to encrypt it with the help of a secret key. The encrypted text was hide in the red plane of the cove image after generating random numbers by applying rules 30, 60, 90 as a hybrid cellular automata using the same secret key as an initial seed. The results were tested on a number of images that shown that the algorithm hide the secret text in the images without distorting it clearly, the algorithm also retrieved the entire secret text without any loss. It was concluded that the use of hybrid cellular automata is better in generating random numbers than using uniform cellular automata.  It was also concluded that applying the retrieval algorithm with any minor changes in the value of the secret key affects the output of the decryption and the output of random number generation and causes a significant difference in the retrieved text.