Distillation of secret key and entanglement from quantum states

dc.creatorDevetak, Igor
dc.creatorWinter, Andreas
dc.date2003-06-11
dc.date.accessioned2026-07-07T06:07:06Z
dc.date.available2026-07-07T06:07:06Z
dc.descriptionWe study and solve the problem of distilling secret key from quantum states representing correlation between two parties (Alice and Bob) and an eavesdropper (Eve) via one-way public discussion: we prove a coding theorem to achieve the "wire-tapper" bound, the difference of the mutual information Alice-Bob and that of Alice-Eve, for so-called cqq-correlations, via one-way public communication. This result yields information--theoretic formulas for the distillable secret key, giving ``ultimate'' key rate bounds if Eve is assumed to possess a purification of Alice and Bob's joint state. Specialising our protocol somewhat and making it coherent leads us to a protocol of entanglement distillation via one-way LOCC (local operations and classical communication) which is asymptotically optimal: in fact we prove the so-called "hashing inequality" which says that the coherent information (i.e., the negative conditional von Neumann entropy) is an achievable EPR rate. This result is well--known to imply a whole set of distillation and capacity formulas which we briefly review.
dc.description17 pages LaTeX, 1 drawing (eps)
dc.identifierhttps://arxiv.org/abs/quant-ph/0306078
dc.identifierhttp://arxiv.org/abs/quant-ph/0306078
dc.identifierProc. R. Soc. Lond. A, vol 461, pp 207--235, 2005.
dc.identifierdoi:10.1098/rspa.2004.1372
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/91173
dc.subjectQuantum Physics
dc.titleDistillation of secret key and entanglement from quantum states
dc.typetext

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