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Quantum Key Distribution with Classical Bob

Michel Boyer·Dan Kenigsberg·Tal Mor
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Abstract

Secure key distribution among two remote parties is impossible when both are classical, unless some unproven (and arguably unrealistic) computation-complexity assumptions are made, such as the difficulty of factorizing large numbers. On the other hand, a secure key distribution is possible when both parties are quantum. What is possible when only one party (Alice) is quantum, yet the other (Bob) has only classical capabilities? We present a protocol with this constraint, and prove its robustness against attacks: we prove that any attempt of an adversary to obtain information (and even a tiny amount of information) necessarily induces some errors that the legitimate users could notice.

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Michel Boyer, Dan Kenigsberg, Tal Mor. 2007-03-13. Quantum Key Distribution with Classical Bob. https://doi.org/10.1103/physrevlett.99.140501

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