Arbitrarily-high-dimensional reconciliation via cross-rotation for continuous-variable quantum key distribution

Abstract

Multidimensional rotation serves as a powerful tool for enhancing information reconciliation and extending the transmission distance in continuous-variable quantum key distribution (CV-QKD). However, the lack of closed-form orthogonal transformations for high-dimensional rotations has limited the maximum reconciliation efficiency to channels with 8 dimensions over the past decade. This paper presents a cross-rotation scheme to overcome this limitation and enable reconciliation in arbitrarily high dimensions, constrained to even multiples of 8. The key treatment involves reshaping the string vector into matrix form and applying orthogonal transformations to its columns and rows in a cross manner, thereby increasing the reconciliation dimension by one order per cross-rotation while significantly reducing the communication overhead over the classical channel. A rigorous performance analysis is also presented from the perspective of achievable sum-rate. Simulation results demonstrate that 64-dimensional cross-rotation nearly approaches the upper bound, making it a recommended choice for practical implementations.

12 pages, 7 figures, Accepted 9 July, 2025, Physical Review A

References in corpus (18)

• Quantum Cryptography
• Gaussian Quantum Information
• Continuous variable quantum cryptography using coherent states
• Quantum key distribution over 25 km with an all-fiber continuous-variable system
• Finite-size analysis of continuous-variable quantum key distribution
• Composable security proof for continuous-variable quantum key distribution with coherent states
• Long Distance Continuous-Variable Quantum Key Distribution with a Gaussian Modulation
• Security of continuous-variable quantum key distribution via a Gaussian de Finetti reduction
• Multidimensional reconciliation for continuous-variable quantum key distribution
• Reconciliation of a Quantum-Distributed Gaussian Key
• Characterization of Collective Gaussian Attacks and Security of Coherent-State Quantum Cryptography
• Continuous-variable quantum key distribution system: past, present, and future
• Any Quantum Network is Structurally Controllable by a Single Driving Signal
• Key Reconciliation with Low-Density Parity-Check Codes for Long-Distance Quantum Cryptography
• Finite-size security of continuous-variable quantum key distribution with digital signal processing
• Continuous-Variable Quantum Key Distribution with Rateless Reconciliation Protocol
• Symmetric blind information reconciliation for quantum key distribution
• Heisenberg-limited eavesdropping on the continuous-variable quantum cryptographic protocol with no basis switching is impossible