Abstract
The advent of quantum computers brings about the need for cryptosystems that can withstand quantum attacks. The QC-MDPC based McEliece cryptosystem is one such post-quantum cryptographic scheme, offering robust security yet posing significant challenges in efficient decoding. Central to these challenges is the selection of an optimal threshold for bit-flipping decoding algorithms. This paper presents a novel approach that applies Particle Swarm Optimization (PSO) to dynamically establish optimal thresholds, thereby aiming to minimize the number of iterations needed for successful decoding. We demonstrate the effectiveness of our method through rigorous simulations, underscoring its potential to enhance the efficiency of the McEliece cryptosystem and comparable post-quantum cryptographic schemes. This research could mark a substantial step towards greater practicality in the realm of post-quantum cryptography.