Path Computation Engine for Quantum Key Distribution
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Solution Overview
Problem
Current optical communications networks face challenges in securely transmitting quantum key distribution (QKD) signals due to interference from high-power data traffic channels, which can compromise the security and performance of QKD channels by causing optical interference and exploiting system implementation vulnerabilities.
Innovation Solution
A path computation engine (PCE) is developed to calculate and configure a quantum key (Qkey) path that is logically and physically different from the traffic path, using random weight values and avoiding repeaters to minimize interference and enhance security, thereby improving QKD performance and security by selecting paths based on unique requirements and constraints for QKD signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the QKD signal and data traffic channel share the same physical medium, then bandwidth resource utilization is improved, but optical interference occurs compromising QKD security and performance
Solution Approach 1:
The network path is segmented into separate QKD signal path and data traffic path. The PCE computes distinct logical paths for quantum key distribution and classical data transmission, preventing optical interference while maintaining efficient resource utilization through separate routing optimization.
Solution Approach 2:
The path computation engine acts as an intermediary that computes and configures separate logical paths for QKD and data traffic. It mediates the routing decisions to ensure physical separation of quantum and classical signals, eliminating optical interference while optimizing overall network resource allocation.
2Object-affected harmful factors
If the QKD signal uses a path different from the traffic path, then optical interference is reduced, but bandwidth resource utilization decreases
Solution Approach 1:
The system dynamically computes and configures separate logical paths for QKD and data traffic based on real-time network conditions and requirements. The PCE adapts path selection to optimize both security (by separating quantum signals from noisy traffic) and resource utilization (by efficiently routing both types of traffic through available network capacity).
3Device complexity
If the same path is used for both QKD and data traffic, then device complexity is reduced, but QKD security is compromised due to interference from high-power data channels
Solution Approach 1:
The path computation engine is designed with multi-functionality to handle both QKD path computation and data traffic path computation. It universally applies path optimization algorithms to different signal types, managing separate logical paths for quantum and classical traffic while maintaining a unified control plane architecture that reduces overall system complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the quantum key distribution rate and length, reduces the probability of successful eavesdropping, and optimizes bandwidth resource utilization by isolating QKD signals from data traffic, ensuring secure and efficient transmission.
Implementation Method 1
In optical communications, the quantum information is encoded over a characteristic of a photon; for example, polarization state, phase or spin.
Implementation Method 2
To exploit the 'no cloning theorem', i.e. impossibility to fully replicate the quantum state of a photon, the principle on which the security of any quantum encryption protocol is based, single photon communication should be used.
Implementation Method 3
The data traffic channel can cause interference with the QKD signal due, for example, to limited isolation of optical filters and Raman backscattering in optical fibre.
Data Source
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AI summary
A path computation engine, PCE, (100) for an optical communications network comprising a plurality of nodes and a plurality of links. The PCE comprises a processor and memory comprising instructions executable by the processor whereby the PCE is operative to: receive a request to configure a quantum key, Qkey, path from a first node to a second node in the optical communications network for a quantum key distribution, QKD, signal for a quantum key for a secure data transmission signal; calculate a feasible Qkey path from the first node to the second node that is logically different to a traffic path from the first node to the second node for the secure data transmission signal, wherein the Qkey path is feasible if an optical signal power originating from the secure data transmission signal within the Qkey path, caused by optical interference of the secure data transmission signal with the QKD signal, is below a predetermined threshold value; and generate a control signal comprising instructions arranged to configure said feasible Qkey path.