Weak coin flipping with small bias

Iordanis Kerenidis; Ashwin Nayak

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Weak coin flipping with small bias

Iordanis Kerenidis·Ashwin Nayak

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Abstract

This note presents a quantum protocol that demonstrates that_weak_ coin flipping with bias approximately 0.239, less than 1/4, is possible. A bias of 1/4 was the smallest known, and followed from the strong coin flipping protocol of [Ambainis 2001]. Protocols with yet smaller bias, approximately 0.207, have independently been discovered [Ambainis 2001, Spekkens and Rudolph 2002]. We also present an alternative strong coin flipping protocol with bias 1/4 with analysis simpler than that of [Ambainis 2001].

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Iordanis Kerenidis, Ashwin Nayak. 2002-07-12. Weak coin flipping with small bias. https://arxiv.org/abs/quant-ph/0206121

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