Horodecki Karol, Horodecki Michał, Horodecki Paweł, Oppenheim Jonathan
Department of Mathematics, Physics and Computer Science, University of Gdańsk, Poland.
Phys Rev Lett. 2005 Apr 29;94(16):160502. doi: 10.1103/PhysRevLett.94.160502. Epub 2005 Apr 26.
We characterize the set of shared quantum states which contain a cryptographically private key. This allows us to recast the theory of privacy as a paradigm closely related to that used in entanglement manipulation. It is shown that one can distill an arbitrarily secure key from bound entangled states. There are also states that have less distillable private keys than the entanglement cost of the state. In general, the amount of distillable key is bounded from above by the relative entropy of entanglement. Relationships between distillability and distinguishability are found for a class of states which have Bell states correlated to separable hiding states. We also describe a technique for finding states exhibiting irreversibility in entanglement distillation.
我们刻画了包含密码学私钥的共享量子态集合。这使我们能够将隐私理论重塑为一种与纠缠操纵中所使用的范式密切相关的范式。结果表明，可以从束缚纠缠态中提取出任意安全的密钥。也存在一些态，其可提取的私钥比该态的纠缠代价要少。一般来说，可提取密钥的量上限由纠缠相对熵界定。对于一类与可分隐藏态相关联的贝尔态的态，我们找到了可蒸馏性与可区分性之间的关系。我们还描述了一种用于找到在纠缠蒸馏中表现出不可逆性的态的技术。
