The authors of a study describing “Unconditionally Secure Quantum Coin Tossing” withdrew the study because, they say, the scheme is insecure. Details:
Unconditionally Secure Quantum Coin Tossing via Entanglement Swapping
Authors: Yong-Sheng Zhang, Chuan-Feng Li, Guang-Can Guo (University of Science and Technology of China)
Comments: Withdraw. The scheme presented is insecure
ABSTRACT: An unconditionally secure quantum cion [sic] tossing protocol for two remote participants via entangled swapping is pre- sented. The security of this protocol is guaranteed by the nonlocal property of quantum entanglement and the classical complexity.