Novel Substitution Box Architectural Synthesis for Lightweight Block Ciphers

This letter proposes three novel substitution box (S-box) architectures for lightweight block ciphers. The proposed S-box architectures are based on the Boolean decomposition to achieve the design tradeoffs. Absorption of the Terminal Nodes property, positive Davio expansion, and Shannon decomposition are explored for the three S-box architectures. The proposed S-box variants are included in the SPN layer of the Midori-64 block cipher to validate their utility for a lightweight cipher. Also, to demonstrate the generality of the proposed logic decomposition approaches, the proposed work is expanded to the composite field architectures for the S-box of AES-128. Compared with state-of-the-art designs, the proposed designs exhibit a reduction of 66%, 36%, and 21% for energy, delay, and power metrics.