Design of a Lightweight Cryptographic Scheme for Resource-Constrained Internet of Things Devices

We propose an ultra-lightweight cryptographic scheme called "Small Lightweight Cryptographic Algorithm (SLA)". The SLA relies on substitution-permutation network (SPN). It utilizes 64-bit plaintext and supports a key length of 80/128-bits. The SLA cipher includes nonlinear layers, XOR operations, and round permutation layers. The S-box serves to introduce nonlinearity in the entire scheme design. It plays a vital role in increasing the complexity and robustness of the design. The S-box can thwart attacks such as linear and differential attacks. The scheme makes it possible to breed many active S-boxes in a short number of rounds, hindering analytical attacks on the cipher. When compared to other currently used ciphers, SLA has a higher throughput. Additionally, we demonstrate the SLA's performance as an ultra-lightweight compact cipher, and its security analysis. The SLA cipher's design is well suited for applications where small-scale embedded system dissipation is critical. The SLA algorithm is implemented using Python.