QKD Hardware Components

Piller, Ernst; Schölnast, Hubert

Content of this appendix

Appendix 05 · QKD Hardware Components

This appendix examines the hardware foundation of QKD systems. It describes components such as photon sources, lasers, modulators, interferometers, single-photon detectors, random-number sources, synchronization units, and optical channels. The focus is on how these components shape the achievable distance, key rate, stability, and security of practical systems.

The appendix links hardware choices to implementation risks. Detector behavior, calibration, timing, optical power, side channels, and component imperfections can undermine assumptions made in protocol descriptions. The material therefore helps readers understand why a theoretically secure protocol still requires careful engineering and validation.

The hardware overview is particularly useful for evaluating product claims and field deployments. It explains why QKD performance depends on attenuation, environmental stability, maintenance, component aging, and trusted-node or KMS integration. The appendix treats hardware as a core part of the security argument, not merely as equipment around the protocol.

Describes key QKD optical and electronic components
Connects hardware choices to distance and key rate
Highlights detector and calibration vulnerabilities
Explains side-channel relevance in real systems
Supports practical assessment of QKD products

Suggested citation

Reference in IEEE style

E. Piller and H. Schölnast, “Appendix 05: QKD Hardware Components,” author-maintained supplementary material for Data Encryption at the Intersection of Mathematics and Physics: Comparing Physical Methods of Cryptography, 2026. [Online]. Available: https://cryptography.study/phys/QKD-HW/.

Reference in ACM style

Ernst Piller and Hubert Schölnast. 2026. Appendix 05: QKD Hardware Components. Author-maintained supplementary material for Data Encryption at the Intersection of Mathematics and Physics: Comparing Physical Methods of Cryptography. https://cryptography.study/phys/QKD-HW/

BibTeX entry

@misc{piller_schoelnast_2026_appendix_05_qkd_hardware,
  title        = {QKD Hardware Components},
  author       = {Ernst Piller and Hubert Schölnast},
  year         = {2026},
  howpublished = {Author-maintained supplementary material for Data Encryption at the Intersection of Mathematics and Physics},
  url          = {https://cryptography.study/phys/QKD-HW/},
  note         = {Related book DOI: 10.1007/978-3-032-24764-3},
  language     = {en}
}

RIS entry

TY  - GEN
TI  - QKD Hardware Components
T2  - Author-maintained supplementary material for Data Encryption at the Intersection of Mathematics and Physics
AU  - Piller, Ernst
AU  - Schölnast, Hubert
PY  - 2026
UR  - https://cryptography.study/phys/QKD-HW/
N1  - Related book DOI: 10.1007/978-3-032-24764-3
LA  - en
ER  -

CSL JSON entry

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