Tuesday, July 30, 2013

1307.7318 (Guang Ping He)

Secure quantum bit commitment against empty promises. II. The density

Guang Ping He
We further study the security of the quantum bit commitment (QBC) protocol we previously proposed [Phys. Rev. A 74, 022332 (2006).], by analyzing the reduced density matrix \rho_{b}^{B} which describes the quantum state at Bob's side corresponding to Alice's committed bit b. It is shown that Alice will find \rho_{0}^{B}\perp \rho_{1}^{B} while the protocol remains concealing to Bob. On the contrary, the existing no-go theorem of unconditionally secure QBC is based on the condition \rho_{0}^{B}\simeq \rho_{1}^{B}. Thus the specific cheating strategy proposed in the no-go theorem does not necessarily applies to our protocol.
View original: http://arxiv.org/abs/1307.7318

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