Architecture: Quantum-Safe 6G Core (QKDN)

🛰️ Quantum-Safe Topology

graph TB
    subgraph Core [User Data Network (5G/6G Core)]
        AMF[AMF/SMF] --- UPF[UPF Node]
        UPF --- UE[User Equipment]
    end

    subgraph QKDN [Quantum Key Distribution Network]
        direction TB
        QKM1[Key Manager - Central] --- QKM2[Key Manager - Edge]
        QKM1 --- QNode1[QKD Node - Central]
        QKM2 --- QNode2[QKD Node - Edge]
        QNode1 -. "Quantum Link (Photons)" .- QNode2
    end

    QKM1 -- "Secure Management Keys" --> AMF
    QKM2 -- "Secure Data Keys" --> UPF

📑 Architectural Layers

1. The Quantum Layer (Physical)

• Recommendation: Y.3802 (Clause 7.1).
• Function: Establishing the actual quantum link (e.g., using BB84 or Entanglement-based protocols) between two physical QKD Nodes.
• Security Value: Secure against any computational processing power, including quantum computers.

2. The Key Management Layer (Logical)

• Recommendation: Y.3803 (Clause 8).
• Function: Buffers, stores, and manages the keys produced by the Quantum Layer.
• Security Value: Ensures that keys are only delivered to authorized network functions (AMF/UPF) via a secure internal interface (QKDN-KM).

3. The Control & Management Layer

• Recommendation: Y.3813.
• Function: Orchestrates the quantum routes and manages the lifecycle of the keys.
• Security Value: A centralized SDN Controller for the Quantum Overlay.

!NOTETactical Insight: In a hybrid deployment, the User Plane (UPF) receives high-volume keys from a local QKDN Edge node, while the Control Plane (AMF) receives management keys from the Central QKDN Hub.