Applied Journal of Physical Science

Providing privacy between two or more communicating parties on the Internet has been a major area of concern in our modern society due to the high cyber-attack rate. Some of this information is highly confidential and must be protected when it is stored in a computer and when it is in transit over the Internet. Cryptography has generally been acknowledged as the best method of information protection. Studies have shown that among the systems showing chaotic behaviour, 3-D continuous-time chaotic systems are found to contain abundant chaotic structures and complex dynamical behaviour which are highly useful in data security and hence, the need to explore the Rössler system. This paper proposed an image encryption algorithm for RGB images using the 3-D Rössler chaotic system. The proposed algorithm adopts the classic framework of the permutation substitution network in cryptography by using the rich chaotic properties of the Rössler system. This ensures both confusion and diffusion properties for a secure cipher. A standard test image namely Lena_colour_256.tif was used in testing the proposed scheme. Security analyses such as the Histogram Uniformity Analysis, Correlation Coefficient Analysis, Number of Pixels Change Rate (NPCR), and Unified Averaged Changing Intensity (UACI) were carried out on the proposed scheme. Results obtained from the analysis show that the proposed scheme is effective and strong against statistical, differential, and brute-force attacks.