Optimized ۸-bit Quantum S-Box Design via Multiplicative Inverse and Affine Transformation with Enhanced Fidelity and Reduced Gate Complexity

In this study, an ۸-bit quantum S-Box was designed and implemented based on multiplicative inverse operation and affine transformation. The purpose of this design was to increase the non-linearity and uniform distribution of bits in the output and reduce the complexity of the quantum circuit. To evaluate the performance, the depolarized noise model was applied with an error rate of p=۰.۰۱ and the fidelity of the circuit was calculated with the ideal state. The results show that Fidelity increased to ۰.۹۸۷ and compared to the reference version, the number of T gates decreased by ۱۸% and the depth of the circuit decreased by about ۱۵%. Graphical analysis of bit distribution and non-linearity spectrum confirmed improved uniformity and higher resistance to linear and differential attacks. These optimizations show that the proposed method can be used as an effective block in quantum cryptography algorithms.

کلیدواژه ها:

Quantum S-Box ، Nonlinearity Enhancement ، Affine Transformation ، Quantum Cryptography