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Full Security of Quantum Key Distribution From No−Signaling Constraints

Lluis Masanes‚ Renato Renner‚ Matthias Christandl‚ Andreas Winter and Jonathan Barrett

Abstract

We analyze a cryptographic protocol for generating a distributed secret key from correlations that violate a Bell inequality by a sufficient amount, and prove its security against eavesdroppers, constrained only by the assumption that any information accessible to them must be compatible with the non-signaling principle. The claim holds with respect to the state-of-the-art security definition used in cryptography, known as universally-composable security. The non-signaling assumption only refers to the statistics of measurement outcomes depending on the choices of measurements; hence security is independent of the internal workings of the devices - they do not even need to follow the laws of quantum theory. This is relevant for practice as a correct and complete modeling of realistic devices is generally impossible. The techniques developed are general and can be applied to other Bell inequality-based protocols. In particular, we provide a scheme for estimating Bell-inequality violations when the samples are not independent and identically distributed. © 2014 IEEE.

ISSN
0018−9448
Journal
IEEE Transactions on Information Theory
Keywords
Quantum mechanics‚cryptographic protocols‚cryptography‚quantum entanglement‚random number generation
Month
aug
Number
8
Pages
4973–4986
Volume
60
Year
2014