International Conference on Noise and Fluctuations

Making the eavesdropper's life harder

Gergely Vadai, László B. Kish

Published Aug 21, 2019• 0 citations

Abstract

The unconditionally (that is, information theoretically) secure Kirchhoff-law-Johnson-noise (KLJN) key exchanger operates with two pairs of resistors, one at Alice's side and another one at Bob's end.Whenever the cable resistance is not negligible, the original scheme leaks information to the eavesdropper (Eve).The typical way to reduce this leak is treating the exchanged key by privacy amplification.In the present work our goal is to reduce the leak earlier, during the bit exchange level.So far, the common belief has been that the resistance values in Alice's/Bob's pairs should be very different for an easy separation of the bit values to yield low bit error probability in the key exchange.However, such situation is helping Eve during all the currently known types of attacks owing to higher information leak.We explore the possibility of enhancing the security by narrowing the difference between the resistance values.The impact on security and the cost of reduced communication speed are demonstrated for the Bergou-Scheuer-Yariv attack.

DOI: 10.5075/epfl-iclab-icnf-269190

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