Relativistic Quantum Cryptography

Abstract

Quantum key distribution (QKD) is a concept of secret key exchange supported by fundamentals of quantum physics. Its perfect realization offers unconditional key security, however, known practical schemes are potentially vulnerable if the quantum channel loss exceeds a certain realization-specific bound. This discrepancy is caused by the fact that any practical photon source has a non-zero probability of emitting two or more photons at a time, while theory needs exactly one. We report an essentially different QKD scheme based on both quantum physics and theory of relativity. It works flawlessly with practical photon sources at arbitrary large channel loss. Our scheme is naturally tailored for free-space optical channels, and may be used in ground-to-satellite communications, where losses are prohibitively large and unpredictable for conventional QKD.

7 pages, 6 figures

References in corpus (12)

• Quantum Cryptography
• The Security of Practical Quantum Key Distribution
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• Quantum Cryptography Based on Orthogonal States
• Coding Theorems for Quantum Channels
• Unconditionally Secure Bit Commitment
• Unconditionally Secure Bit Commitment by Transmitting Measurement Outcomes
• Experimental bit commitment based on quantum communication and special relativity
• Experimental quantum cryptography scheme based on orthogonal states
• Quantum Cryptography with Orthogonal States?
• Role of causality in ensuring unconditional security of relativistic quantum cryptography

Cited by in corpus (4)

• Attacks exploiting deviation of mean photon number in quantum key distribution and coin tossing
• Accessible and inaccessible quantum coherence in relativistic quantum systems
• Security of differential phase shift QKD from relativistic principles
• Making two particle detectors in flat spacetime communicate quantumly