Continuous variable direct secure quantum communication using Gaussian states

TL;DR

This paper introduces new continuous variable quantum communication schemes using Gaussian states, demonstrating their security and versatility without requiring two-mode squeezed states, and highlighting their potential for broader cryptographic applications.

Contribution

The paper proposes novel continuous variable quantum secure communication and controlled quantum dialogue schemes using single-mode squeezed coherent states, avoiding the need for two-mode squeezed states.

Findings

Schemes are secure against Gaussian quantum cloning and intercept-resend attacks.

Proposed schemes can be reduced to various cryptographic tasks like quantum key distribution.

They do not require two-mode squeezed states, simplifying implementation.

Abstract

Continuous variable one-way and controlled-two-way secure direct quantum communication schemes have been designed using Gaussian states. Specifically, a scheme for continuous variable quantum secure direct communication and another scheme for continuous variable controlled quantum dialogue are proposed using single-mode squeezed coherent states. The security of the proposed schemes against a set of attacks (e.g., Gaussian quantum cloning machine and intercept resend attacks) has been proved. Further, it is established that the proposed schemes do not require two-mode squeezed states which are essential for a set of existing proposals. The controlled two-way communication scheme is shown to be very general in nature as it can be reduced to schemes for various relatively simpler cryptographic tasks like controlled deterministic secure communication, quantum dialogue, quantum key distribution. In addition, it is briefly discussed that the proposed schemes can provide us tools to design quantum cryptographic solutions for several socioeconomic problems.