LAUSR

The Internet of Things (IoT) poses stringent requirements on service quality and security strength. A highly reliable encryption algorithm with low complexity is required to ensure information security. Therefore, this paper proposes a complexity-reduced secure and fast encryption routine (SAFER)-Fermat block encryption method that accounts for the confusion and diffusion principles. In particular, a novel diffusion layer that exploiting the Fermat number theory transform is proposed, while the confusion layer remains unchanged as the SAFER algorithm. We also propose two data record structures to accommodate the two layers and deal with the overflow issue. The proposed scheme only considers the integer operation, the inclusion of multipliers in our study is no longer necessary, thereby resulting in low complexity and lightweight encryption method. Therefore, the proposed encryption method is advantageous for power-limited IoT devices. The simulations demonstrate that the proposed encryption method maintains the security of the SAFER++ method but requires fewer computations.