Confused Memory Read Attracts Synthetic Diffusion on the Fly – A Lightweight Image Encryption for IoT Platform

The analogous growth of threat and data communication among the connected devices invites specialised security algorithms for Internet of Things (IoT). The minimal computational capabilities and resource constraints of the processing devices used in IoT architecture do not afford the overhead incurred by the conventional encryption schemes. This paper proposes a lightweight image encryption algorithm that can be realised as an embedded software to run on microcontroller architectures suitable for IoT applications. The proposed algorithm uses the pseudo-random numbers produced by the Linear Feedback Shift Register (LFSR) to perform inherent confusion on the fly via random memory read. A synthetic image generated by extracting the random bits produced by the digitised Lorenz attractor has been used to diffuse the confused pixels on the fly. The proposed algorithm has been realised as embedded software to run on microcontrollers suitable for Internet of Things (IoT) applications. The proposed algorithm achieves better results than similar reliable encryption schemes in terms of security parameters such as entropy, correlation, histogram, PSNR, NPCR and UACI. Further, eliminating the storage of confusion and diffusion key beside the storage of encrypted image employing on the fly encryption process proposed in our algorithm reduces the demand on RAM for about 48 KB as compared to the conventional storage-based encryption schemes.