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A large family of quantum weak coin-flipping protocols

Carlos Mochon
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Abstract

Each classical public-coin protocol for coin flipping is naturally associated with a quantum protocol for weak coin flipping. The quantum protocol is obtained by replacing classical randomness with quantum entanglement and by adding a cheat detection test in the last round that verifies the integrity of this entanglement. The set of such protocols defines a family which contains the protocol with bias 0.192 previously found by the author, as well as protocols with bias as low as 1/6 described herein. The family is analyzed by identifying a set of optimal protocols for every number of messages. In the end, tight lower bounds for the bias are obtained which prove that 1/6 is optimal for all protocols within the family.

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Carlos Mochon. 2005-12-25. A large family of quantum weak coin-flipping protocols. https://doi.org/10.1103/physreva.72.022341

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