Abstract The security and anonymity of e-payment transactions are paramount. In this study, we propose a centralised e-payment protocol based on superdense coding. By adopting quantum key establishment principles inspired by quantum key distribution (QKD) and combining them with superdense coding-based message transmission, symmetric key encryption, and two-particle entanglement, our quantum e-payment protocol utilises Bell states to reduce the complexity of quantum resources. The protocol is used for both key distribution and secure message transmission between the communicating parties. It is also resilient against quantum attacks and provides operational non-repudiation and immutability. Compared to previously proposed protocols, our protocol offers improved security while maintaining practical feasibility for real-world applications.
Çelik et al. (2026) studied this question.