Security analysis of quantum key distribution on passive optical networks

Area of Science:

• Quantum Information Science
• Network Security
• Optical Communications

Background:

• Quantum Key Distribution (QKD) is increasingly deployed in access networks like passive optical networks (PONs).
• Optical power splitters in PONs pose challenges to secure key rates in QKD.
• Existing QKD research for access networks prioritizes implementation over protocol-level enhancements for key rates.

Purpose of the Study:

• To develop a novel QKD protocol for enhancing secure key rates in passive optical networks.
• To address the limitations of existing protocols in managing security and key rates within PONs.
• To propose a protocol that overcomes theoretical secure key rate limits imposed by conventional methods.

Main Methods:

• Extended the secure key rate formula of the decoy-state BB84 protocol for passive optical networks.
• Introduced a cooperative approach among end-users within the passive optical network.
• Analyzed the protocol's resilience against photon number splitting (PNS) attacks.

Main Results:

• The proposed protocol enhances secure key rates compared to conventional methods.
• The cooperative approach effectively mitigates photon number splitting (PNS) attacks.
• Multi-photon states can be utilized for secure key generation, unlike in the standard decoy BB84 protocol.

Conclusions:

• The developed QKD protocol offers a significant improvement in secure key rates for passive optical networks.
• The protocol's ability to leverage multi-photon states and mitigate PNS attacks represents a key advancement.
• This research highlights the importance of protocol development for optimizing QKD performance in access network environments.