CAChaIoT: Hybrid lightweight image encryption for IoT using cellular automata and chaotic maps
Biswarup Yogi, Ajoy Kumar Khan
Abstract
With the rise of the Internet of Things (IoT), the protection of image data is a challenging task due to the limited resources of the devices and the ability to process data in an efficient and timely manner. The proposed lightweight image encryption scheme uses Cellular Automata Rule 30 and the Tinkerbell map within the same framework to deliver both adequate data protection and computational efficiency. The work begins by dividing the image into its red, green, and blue RGB channels, starting with Tinkerbell map-based encryption, followed by Cellular Automata Rule 30-based encryption for improved diffusion. We implemented the method and achieved a very high level of encryption, as evidenced by an NPCR (Number of Pixels Change Rate) of 99.6261, which assures strong security.. The proposed algorithm achieves strong security metrics, including a UACI of 49.86%, which exceeds the baseline of 33.33% and indicates high sensitivity to input changes, making it robust against differential attacks. This method is ideal in IoT devices because it is efficient and simple. Future studies can explore the inclusion of other cryptographic methods, as well as optimisation on different IoT platforms to achieve better scalability and security.