Decoherence can help quantum cryptographic security

Abstract

In quantum key distribution, one conservatively assumes that the eavesdropper Eve is restricted only by physical laws, whereas the legitimate parties, namely the sender Alice and receiver Bob, are subject to realistic constraints, such as noise due to environment-induced decoherence. In practice, Eve too may be bound by the limits imposed by noise, which can give rise to the possibility that decoherence works to the advantage of the legitimate parties. A particular scenario of this type is one where Eve can't replace the noisy communication channel with an ideal one, but her eavesdropping channel itself remains noiseless. Here, we point out such a situation, where the security of the Ping-Pong protocol (modified to a key distribution scheme) against a noise-restricted adversary improves under a non-unital noisy channel, but deteriorates under unital channels. This highlights the surprising fact that, contrary to the conventional expectation, noise can be helpful to quantum information processing. Furthermore, we point out that the measurement outcome data in the context of the non-unital channel can't be simulated by classical noise locally added by the legitimate users.

9 pages, 3 figures; Close to the published version

References in corpus (14)

• Eavesdropping on the "ping-pong" type quantum communication protocols with invisible photon
• Multi-step quantum secure direct communication using multi-particle Green-Horne-Zeilinger state
• Direct and Reverse Secret-Key Capacities of a Quantum Channel
• Three-party quantum secure direct communication based on Greenberger-Horne-Zeilinger states
• Continuous-variable quantum key distribution protocols over noisy channels
• The squeezed generalized amplitude damping channel
• Quantum cryptography: key distribution and beyond
• On the Security of the Ping-Pong Protocol
• A comparative study of protocols for secure quantum communication under noisy environment: single-qubit-based protocols versus entangled-state-based protocols
• Quantum money with nearly optimal error tolerance
• Symmetry-noise interplay in quantum walk on an n-cycle
• Security of modified Ping-Pong protocol in noisy and lossy channel
• An environment-mediated quantum deleter
• A general scheme for information interception in the ping pong protocol

Cited by in corpus (6)

• Analysis of atmospheric effects on satellite based quantum communication: A comparative study
• Hierarchy of quantum correlations under non-Markovian dynamics
• Quantum Communication using Code Division Multiple Access Network
• Ping-pong quantum key distribution with trusted noise: non-Markovian advantage
• Distinguishing environment-induced non-Markovianity from subsystem dynamics
• Quantum security and theory of decoherence