Resource requirements and speed versus geometry of unconditionally secure physical key exchanges

Elias Gonzalez, Robert Balog, Laszlo B. Kish

Research output: Contribution to journalArticle

4 Citations (Scopus)


The imperative need for unconditional secure key exchange is expounded by the increasing connectivity of networks and by the increasing number and level of sophistication of cyberattacks. Two concepts that are theoretically information-secure are quantum key distribution (QKD) and Kirchoff-Law-Johnson-Noise (KLJN). However, these concepts require a dedicated connection between hosts in peer-to-peer (P2P) networks which can be impractical and or cost prohibitive. A practical and cost effective method is to have each host share their respective cable(s) with other hosts such that two remote hosts can realize a secure key exchange without the need of an additional cable or key exchanger. In this article we analyze the cost complexities of cable, key exchangers, and time required in the star network. We mentioned the reliability of the star network and compare it with other network geometries. We also conceived a protocol and equation for the number of secure bit exchange periods needed in a star network. We then outline other network geometries and trade-off possibilities that seem interesting to explore.

Original languageEnglish
Pages (from-to)2010-2024
Number of pages15
Issue number4
Publication statusPublished - 2015
Externally publishedYes



  • Information theoretically secure
  • KLJN
  • Networks
  • QKD
  • Secure key exchange
  • Star network
  • Unconditional security

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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