Twin-field quantum encryption protocol for E-payment based on blockchain

Electronic payment (E-payment) systems rely heavily on secure communication, typically achieved through encryption processes in cryptography. Traditional cryptography often relies on complex mathematical problems for encryption, such as difficult decompositions or extracting discrete logarithms. With the development of quantum computing, the security of these classical encryption methods is under threat. To address this challenge, quantum E-payment protocols have emerged as a potential solution. However, the practical quantum E-payment protocols are limited due to the channel transmission efficiency decreasing exponentially with distance. This is further constrained by the Pirandola-Laurenza-Ottaviani-Banchi (PLOB) bound. To address this challenge, we propose a twin-field quantum encryption protocol for E-payment based on blockchain. In our protocol, we propose a twin-field quantum encryption method to authenticate identity and detect eavesdropping simultaneously. It not only eliminates side-channel attacks on the detectors but also has the potential to break the PLOB bound. Our security analysis shows that our E-payment protocol exhibits security properties such as blindness, unforgeability, and undeniability. Furthermore, our protocol demonstrates withstand against common inside and outside attacks.