The Impossibility of Efficient Quantum Weak Coin-Flipping
Colloquium featuring Carl Alexander Miller - QuICS and NIST
How can two parties carry out a fair coin flip across a noiseless quantum channel? In 2007, Carlos Mochon proved a tantalizing result: he showed that fair quantum coin flipping is possible in principle, but he used a protocol that required a huge (exponential) number of communication rounds. In the twelve years since, despite some continued deep theoretical work on the problem, no improvements to the efficiency of Mochon's protocol have been made.