In the current era, major technology is cloud computing and Internet of Things due to their vast applications in day-to-day life. The major reason behind today’s internet traffic is big data transmission and usage in varied data types like textual, image and video datasets, as well as audio data. Due to widely spread usage of social media, security and authenticity of image data is of utmost priority especially when it comes to applications like medical images, Geographic imaging system, biometric authenticity. The major objective of this research is to provide a sustainable robust encryption algorithm for securing images where data authenticity is of priority like biometric images. Algorithm is lightweight cryptographic algorithm as it uses low dimensional chaotic map Arnold’s CAT map (ACM) and \(\mathscr {L}\) -System fractal for key generation. The results tabulated show satisfactory output towards statistical tests. Robustness and effectiveness of the proposed algorithm is compared decently with other existing algorithms and it demonstrates practical usability of the algorithm.