A Lightweight Semi-quantum E‑payment Protocol Based on Blockchain

How to apply E-payment based on quantum cryptography to our daily life is a significant problem. Inspired by the semi-quantum protocols, we present a lightweight semi-quantum E-payment protocol based on blockchain. Our protocol has the following advantages: First, by using semi-quantum cryptography, a classic user Alice can transfer information according to Bell state generated by semi-quantum user Trent. This eliminates the need for participants to have full-quantum capabilities and makes our protocol easier to implement. Moreover, the classic user Alice can perform payment operations on the mobile device. Second, we use controlled quantum teleportation to ensure the anonymity of payment information. Then, three-qubit entangled states are used to make it easier to prepare quantum resources. At last, blockchain technology ensures the traceability of messages. For security, eavesdropping will undoubtedly be found when the n-bits message is large enough. In addition, the analysis results show that the protocol is secure against some eavesdropping attacks and more lightweight than the existing E-payment protocols.