This project addresses the challenge of implementing secure quantum communication in resource-constrained environments such as IoT nodes, wearable devices, and smart sensors. These systems increasingly require high-performance cryptography that is compatible with limited memory and processing power. We propose and analyze a continuous-variable quantum key distribution (CV-QKD) framework that delivers composable security while tightly characterizing the error correction (EC) leakage and storage demands of such devices.

By focusing on Gaussian-modulated coherent-state (GMCS) protocols and enhancing the post-processing stage with non-binary LDPC codes, our work achieves secret key rates close to the theoretical optimum. We develop tight finite-size bounds for the one-way EC stage and connect them to memory predictions needed for encoding parity-check matrices, enabling practical deployments of CV-QKD on constrained transmitters communicating with more capable receivers.

Objectives

  • Develop a composable security framework for CV-QKD suitable for constrained devices.
  • Apply tight finite-size bounds to model realistic EC leakage using non-binary LDPC codes.
  • Analyze memory and performance trade-offs in encoding procedures.
  • Offer theoretical predictions and simulations for storage-efficient EC encoding.
  • Evaluate practical viability through rate vs resource consumption plots under real-world constraints.

Funding

This research is supported in part by:

  • EPSRC and DSIT TMF-uplift, under the CHEDDAR Hub: Communications Hub For Empowering Distributed ClouD Computing Applications And Research (Grant references: EP/X040518/1, EP/Y037421/1).

Publications

Codebase