Strengthening IoT Security: An Analysis of the Security-related Properties of Power Function-based 5-bit S-box Cryptographic Design

Internet of Things (IoT) devices are growing rapidly and pose significant security risks, including threats from unauthorized access, malware, and data breaches. Cryptographic mechanisms, particularly encryption, are essential in safeguarding IoT systems. This paper explores the cryptographic design and security properties of 5-bit S-boxes, a substitution component less common due to its odd size. We generate 5-bit S-boxes based on the power function. Furthermore, we evaluate the enhanced security properties of the S-box against differential, linear, boomerang, algebraic, truncated differential, subspace trace, cube, and cube-like attacks using Peigen. The results showed that 20 S-boxes based on power functions classified as Almost Bent (AB) functions offered the most robust protection against differential, boomerang, and linear attacks. These S-boxes provide varying levels of security, but they are strong enough to protect against algebraic, truncated differential, subspace trail, cube, and cube-like attacks. Our findings contribute to improved security for IoT devices in resource-constrained environments.