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A simple proof of the unconditional security of relativistic quantum cryptography

S. N. Molotkov·S. S. Nazin
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Abstract

A simple proof of the unconditional security of a relativistic quantum cryptosystem based on orthogonal states is proposed. Restrictions imposed by special relativity allow to substantially simplify the proof compared with the non-relativistic cryptosystems involving non-orthogonal states. Important for the proposed protocol is the spatio-temporal structure of the quantum states which is actually ignored in the non-relativistic protocols employing only the structure of the state space of the information carriers. As a consequence, the simplification arises because of the inefficiency of collective measurements which constitute the major problem in the non-relativistic case.

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S. N. Molotkov, S. S. Nazin. 2000-12-15. A simple proof of the unconditional security of relativistic quantum cryptography. https://doi.org/10.1134/1.1378181

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