Simultaneous classical communication and quantum key distribution based on gaussian modulated coherent states

Youngjun Kim, Young Chai Ko

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


We propose a new quantum communication scheme using quantum coherent states. In our scheme, classical information and the secret key are transmitted simultaneously without any loss of secret key rate performance, while only the secret key is transmitted in the conventional protocol. In our protocol, classical information is first modulated by pulse amplitude modulation (PAM). The secret key is then mapped by random Gaussian modulation and is added to the PAM symbol. The receiver decodes the classical information, treating the Gaussian signal as additive noise. The classical symbol is discarded from the received state after successive decoding of the classical information, and the secret key is then distilled by conventional protocol. We demonstrate that after the classical symbol is discarded, the remaining system is identical to the conventional quantum key distribution system. Our proposed scheme provides the same secret key rate as that of the conventional quantum key distribution system and provides an additional data rate of classical information.

Original languageEnglish
Article number20160680
Journalieice electronics express
Issue number16
Publication statusPublished - 2016

Bibliographical note

Publisher Copyright:
© IEICE 2016.


  • Coherent states
  • Continuous variable quantum key distribution (CV-QKD)
  • Homodyne detector

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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