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Secure quantum key distribution using squeezed states

Daniel Gottesman·John Preskill
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Abstract

We prove the security of a quantum key distribution scheme based on transmission of squeezed quantum states of a harmonic oscillator. Our proof employs quantum error-correcting codes that encode a finite-dimensional quantum system in the infinite-dimensional Hilbert space of an oscillator, and protect against errors that shift the canonical variables p and q. If the noise in the quantum channel is weak, squeezing signal states by 2.51 dB (a squeeze factor e^r=1.34) is sufficient in principle to ensure the security of a protocol that is suitably enhanced by classical error correction and privacy amplification. Secure key distribution can be achieved over distances comparable to the attenuation length of the quantum channel.

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Daniel Gottesman, John Preskill. 2000-09-25. Secure quantum key distribution using squeezed states. https://doi.org/10.1103/physreva.63.022309

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