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Appendix 08 · RKD: Radio-Signal Key Distribution

From the book: Data Encryption at the Intersection of Mathematics and Physics – Comparing Physical Methods of Cryptography

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Content of this appendix

Appendix 08 · RKD: Radio-Signal Key Distribution

This appendix expands the RKD discussion with implementation-oriented detail. It explains how radio measurements are collected, compared, and converted into key material, and it places practical experiments and device development in the context of physical-layer key generation.

The material covers measurement campaigns, channel behavior, motion, sampling, quantization, error correction, privacy amplification, and attacker analysis. It shows that the practical quality of RKD depends not only on radio reciprocity but also on signal processing choices and the ability to handle real channel conditions.

The appendix also considers deployment and cost. RKD can use compact and inexpensive hardware and is attractive for mobile or local communication scenarios, but it remains limited by range, key rate, movement requirements, and immature standardization. The result is a practical engineering view of RKD rather than a purely theoretical one.

  • Explains RKD measurements and key extraction
  • Covers quantization, correction, and privacy amplification
  • Analyzes attacker assumptions and channel conditions
  • Highlights mobile and low-cost use cases
  • Identifies deployment and standardization limits

Suggested citation

Reference in IEEE style

E. Piller and H. Schölnast, “Appendix 08: RKD: Radio-Signal Key Distribution,” 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/RKD/.

Reference in ACM style

Ernst Piller and Hubert Schölnast. 2026. Appendix 08: RKD: Radio-Signal Key Distribution. Author-maintained supplementary material for Data Encryption at the Intersection of Mathematics and Physics: Comparing Physical Methods of Cryptography. https://cryptography.study/phys/RKD/

BibTeX entry 
@misc{piller_schoelnast_2026_appendix_08_rkd,
  title        = {RKD: Radio-Signal Key Distribution},
  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/RKD/},
  note         = {Related book DOI: 10.1007/978-3-032-24764-3},
  language     = {en}
}
RIS entry 
TY  - GEN
TI  - RKD: Radio-Signal Key Distribution
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/RKD/
N1  - Related book DOI: 10.1007/978-3-032-24764-3
LA  - en
ER  -
CSL JSON entry 
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