This research proposed MSBK, a novel key generation approach that introduces the split-radix butterfly architecture of fast Fourier transformation (FFT) in the field of cryptography. The MSBK cipher modified the butterfly architecture to fit accurately into cryptography. However, butterfly architecture has a higher avalanche effect which creates generated keys enough strong to protect information from different online and offline attacks. It also meets the standard of the Shannon properties: Confusion and diffusion. The proposed MSBK cipher consumes less power than earlier works. The MSBK technique’s memory consumption and execution cycle were assessed using the FELICS (Fair Evaluation of Lightweight Cryptographic Systems) program, which operates on the Linux operating system. The suggested MSBK technique has also been simulated in MATLAB 2021a to evaluate the key sensitivity of multiple original and encrypted images using the histogram, correlation graph, and entropy. The negative correlation coefficient of images encrypted by the proposed cipher indicates that the differential and statistical attacks are quite impossible for an intruder. Furthermore, the number of change in pixel rate (NPCR) and the unified average change of intensity (UACI) parameters show that the suggested MSBK approach is robust to different statistical attacks.