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Secret quantum communication of a reference frame

Giulio Chiribella·Lorenzo Maccone·Paolo Perinotti
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Abstract

We propose quantum cryptographic protocols to secretly communicate a reference frame- unspeakable information in the sense it cannot be encoded into a string of bits. Two distant parties can secretly align their Cartesian axes by exchanging N spin 1/2 particles, achieving the optimal accuracy 1/N. A possible eavesdropper cannot gain any information without being detected.

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Giulio Chiribella, Lorenzo Maccone, Paolo Perinotti. 2008-10-22. Secret quantum communication of a reference frame. https://doi.org/10.1103/physrevlett.98.120501

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