Security bounds for efficient decoy-state quantum key distribution

Abstract

Information-theoretical security of quantum key distribution (QKD) has been convincingly proven in recent years and remarkable experiments have shown the potential of QKD for real world applications. Due to its unique capability of combining high key rate and security in a realistic finite-size scenario, the efficient version of the BB84 QKD protocol endowed with decoy states has been subject of intensive research. Its recent experimental implementation finally demonstrated a secure key rate beyond 1 Mbps over a 50 km optical fiber. However the achieved rate holds under the restrictive assumption that the eavesdropper performs collective attacks. Here, we review the protocol and generalize its security. We exploit a map by Ahrens to rigorously upper bound the Hypergeometric distribution resulting from a general eavesdropping. Despite the extended applicability of the new protocol, its key rate is only marginally smaller than its predecessor in all cases of practical interest.

8 pages, 2 figures, 2 tables. Special Issue on Quantum Communication & Cryptography

References in corpus (12)

• Quantum cryptography with finite resources: unconditional security bound for discrete-variable protocols with one-way post-processing
• Coexistence of high-bit-rate quantum key distribution and data on optical fiber
• Squashing Models for Optical Measurements in Quantum Communication
• Upper bounds of eavesdropper's performances in finite-length code with decoy method
• GHz-gated InGaAs/InP single-photon detector with detection efficiency exceeding 55% at 1550 nm
• Security proof for QKD systems with threshold detectors
• Practical long-distance quantum key distribution system using decoy levels
• Practical Evaluation of Security for Quantum Key Distribution
• Experimental quantum key distribution with finite-key security analysis for noisy channels
• Enhancing practical security of quantum key distribution with a few decoy states
• Experimental Decoy State Quantum Key Distribution with Unconditional Security Incorporating Finite Statistics
• Numerical analysis of decoy state quantum key distribution protocols