Laser Physics

Side channels of information leakage in quantum cryptography based on geometrically uniform coherent states

S. N. Molotkov, Kirill A. Balygin

Published May 4, 2020• 3 citations

Abstract

Abstract Quantum key distribution systems are open systems in the sense that in addition to attacking quantum states in the quantum communication channel, the eavesdropper can obtain additional information about the transmitted key using passive radiation detection of the transmitting and receiving stations, as well as active probing of the state of the equipment through a fiber communication line. In this paper, we consider the cryptographic robustness of a quantum cryptography system that uses a protocol with phase coding based on strongly weakened coherent geometrically uniform states. Non-strict single-photon information states, as well as information leakage through side channels, are taken into account by the generalized Decoy State method, taking into account joint collective measurements of information quantum states and quantum states in side channels. An estimate of the secret key length is obtained, which is expressed only in terms of the observed values at the receiving station and the parameters of quantum states in the side channels.

DOI: 10.1088/1555-6611/ab8298

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