A Novel Quantum Coin Tossing Protocol Based on Quantum Public-Key Cryptosystem

Quantum coin tossing is a simple cryptographic primitive with many applications in more complicated tasks and plays a crucial role in complex quantum cryptography protocol design. Coin tossing protocols in classical environment are often based on bit commitment protocol. It has been proved that unconditionally secure quantum bit commitment schemes are insecure. Therefore, quantum coin tossing based on quantum bit commitment protocol isn´t unconditionally secure. In general, quantum coin tossing is strictly weaker than bit commitment. In this paper, we have proposed a quantum coin tossing protocol based on quantum public-key cryptosystems. According to quantum CSS codes, we constructed a class of quantum quasi-cyclic low-density parity-check codes, and then proposed a novel quantum coin tossing protocol. Security analysis show that the proposed protocols are more secure.