[Paper Review] Paving the Way towards 800 Gbps Quantum-Secured Optical Channel Deployment in Mission-Critical Environments

Marco Pistoia, Omar Amer+17 more|arXiv (Cornell University)|Feb 15, 2022

Quantum Information and Cryptography4 citations

TL;DR

This paper demonstrates the first experimental deployment of an 800 Gbps quantum-secured optical channel multiplexed with multiple DWDM channels on the C-band, using QKD on the O-band over up to 100 km of standard fiber. At 70 km, it achieved a 66.16 kbps secret key rate, enabling secure encryption of 258 high-speed data channels with AES-256-GCM, and successfully transported a blockchain application over the quantum-secured link.

ABSTRACT

This article describes experimental research studies conducted towards understanding the implementation aspects of high-capacity quantum-secured optical channels in mission-critical metro-scale operational environments using Quantum Key Distribution (QKD) technology. To the best of our knowledge, this is the first time that an 800 Gbps quantum-secured optical channel -- along with several other Dense Wavelength Division Multiplexed (DWDM) channels on the C-band and multiplexed with the QKD channel on the O-band -- was established at distances up to 100 km, with secret key-rates relevant for practical industry use cases. In addition, during the course of these trials, transporting a blockchain application over this established channel was utilized as a demonstration of securing a financial transaction in transit over a quantum-secured optical channel. The findings of this research pave the way towards the deployment of QKD-secured optical channels in high-capacity, metro-scale, mission-critical operational environments, such as Inter-Data Center Interconnects.

Motivation & Objective

• To validate the feasibility of deploying high-capacity, quantum-secured optical channels in real-world, mission-critical metro-scale networks.
• To demonstrate the coexistence of 800 Gbps classical data channels and a QKD channel on the same fiber using wavelength division multiplexing.
• To evaluate system performance under real-world conditions, including fiber distance, attenuation, and inter-channel interference.
• To prove the practicality of QKD integration in existing network infrastructures without dedicated fiber or new site deployment.
• To demonstrate end-to-end security of a financial transaction using a blockchain application over a quantum-secured optical channel.

Proposed method

• Conducted experiments using real-world operational equipment in a lab testbed at JPMorgan Chase’s Optical Transport Lab, simulating a metro-scale inter-data center link.
• Employed polarization-encoded decoy-state BB84 QKD protocol with a 1310 nm quantum channel on the O-band, multiplexed with 800 Gbps and multiple 100 Gbps DWDM channels on the C-band.
• Used commercial Waveserver systems for high-speed data transmission and a photonic line system to insert additional DWDM channels for interference studies.
• Applied variable optical attenuators (VOAs) to simulate real-world signal loss and assess impact on QKD performance at 1310 nm.
• Deployed a lightweight Liink blockchain application over the 800 Gbps quantum-secured channel, with peer discovery and transaction propagation secured end-to-end.
• Measured secret key rate (SKR), quantum bit error rate (QBER), and system stability across varying distances (up to 100 km) and power levels.

Experimental results

Research questions

• RQ1 Can an 800 Gbps classical data channel be successfully multiplexed with a QKD channel on the same fiber over 100 km of standard SMF-28 G.652.D fiber?
• RQ2 What is the achievable secret key rate (SKR) for QKD when coexisting with high-capacity DWDM channels in a real-world operational environment?
• RQ3 How do fiber length, launch power, and signal attenuation affect the performance of the quantum channel in a co-propagation setup?
• RQ4 Can a production-grade blockchain application be securely transported over a QKD-secured optical channel without additional application-level encryption?
• RQ5 Is it feasible to deploy QKD in existing network infrastructure without dedicated fiber or new site construction?

Key findings

• An 800 Gbps QKD-secured optical channel was successfully established over 100 km of standard single-mode fiber using C-band DWDM and O-band QKD multiplexing.
• At 70 km, the system achieved a secret key rate of 66.16 kbps, sufficient to support 258 QKD-secured 100 Gbps data channels using AES-256-GCM with a 1-second key refresh rate.
• The system maintained stable performance across distances up to 100 km, with launch power increased to 2 dBm at 80–100 km to maintain signal integrity.
• Inter-channel interference was evaluated by inserting additional DWDM channels, confirming minimal impact on QKD performance when properly managed.
• The blockchain application successfully transmitted transactions end-to-end over the quantum-secured channel, with confirmation of receipt and block inclusion verified at the receiver.
• The study confirmed that QKD can be deployed in existing network facilities without dedicated fiber or new site construction, enabling practical integration into mission-critical infrastructures.