Quantum weak coin flipping with arbitrarily small bias

TL;DR

This paper discusses quantum weak coin flipping, a cryptographic protocol allowing two parties to flip a coin with arbitrarily small bias, and provides a tutorial on the underlying formalism.

Contribution

It introduces a method for achieving quantum weak coin flipping with arbitrarily small bias, along with a comprehensive tutorial on the necessary formalism.

Findings

Quantum weak coin flipping can have arbitrarily small bias.

A complete tutorial on Kitaev's formalism is provided.

The protocol advances quantum cryptography capabilities.

Abstract

"God does not play dice. He flips coins instead." And though for some reason He has denied us quantum bit commitment. And though for some reason he has even denied us strong coin flipping. He has, in His infinite mercy, granted us quantum weak coin flipping so that we too may flip coins. Instructions for the flipping of coins are contained herein. But be warned! Only those who have mastered Kitaev's formalism relating coin flipping and operator monotone functions may succeed. For those foolhardy enough to even try, a complete tutorial is included.