Johnson(-like)–Noise–Kirchhoff-loop based secure classical communicator characteristics, for ranges of two to two thousand kilometers, via model-line

Abstract

Abstract.A pair of Kirchhoff-Loop-Johnson(-like)-Noise communicators, which is able to work over variable ranges, was designed and built. Tests have been carried out on a model-line performance characteristics were obtained for ranges beyond the ranges of any known direct quantum communication channel and they indicate unrivalled signal fidelity and security performance of the exchanged raw key bits. This simple device has single-wire secure key generation and sharing rates of 0.1, 1, 10, and 100 bit/second for corresponding copper wire diameters/ranges of 21 mm / 2000 km, 7 mm / 200 km, 2.3 mm / 20 km, and 0.7 mm / 2 km, respectively and it performs with 0.02% raw-bit error rate (99.98 % fidelity). The raw-bit security of this practical system significantly outperforms raw-bit quantum security. Current injection breaking tests show zero bit eavesdropping ability without triggering the alarm signal, therefore no multiple measurements are needed to build an error statistics to detect the eavesdropping as in quantum communication. Wire resistance based breaking tests of BergouScheuer-Yariv type give an upper limit of eavesdropped raw bit ratio of 0.19 % and this limit is inversely proportional to the sixth power of cable diameter. Hao's breaking method yields zero (below measurement resolution) eavesdropping information.Introduction.

Unconditional Security by the Laws of Classical Physics

“…Finally, the application of thermal noise for unconventional informatics, namely for noisebased logic and computing [29][30][31][32][33][34][35][36] and the KJLN secure key exchange [37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52], emerged decades later than the corresponding quantum informatics schemes such as quantum computing [53] and quantum encryption [54][55][56].…”

“…The KLJN secure key exchange scheme was introduced in 2005 [37][38][39] and was built and demonstrated in 2007 [40]; it is founded on the robustness of classical information as well as stochasticity and the laws of classical physics. It was named by its creators the "Kirchhoffloop-Johnson(-like)-Noise" scheme, while on the Internet -in blogs and similar sites, including Wikipedia -it has widely been nicknamed "Kish cypher" or "Kish cipher" (where both designations are wrong).…”

Enhanced Secure Key Exchange Systems Based on the Johnson- Noise Scheme

“…However, in 2005, the Kirchhoff-Law-Johnson-(like)-Noise (KLJN) secure key exchange [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] scheme was introduced [4] and later it was built and its security demonstrated [7]. These ideas have inspired new concepts also in computing, particularly noise-based logic and computing [17][18][19][20][21][22][23][24], where not the security of data but complexity of data processing has been the issue.…”

“…(2,3,7,8) with the actually measured mean-square channel voltage and current to decide if the situation is secure (LH or HL) while utilizing the fact that these mean-square values are different in each of these three situations (LL, LH/HL and HH). If the situation is secure, Alice and Bob will know that the other party has the inverse of his/her bit, which means, a secure key exchange takes place.…”

“…As we have already pointed out above, the minimal duration of the clock period in the original KLJN scheme is set by Alice and Bob by their need to successfully classify the measured mean-square channel voltage and/or current levels by comparing them with the predictions of Eqs. (2,3,7,8) in order to identify that to which one of the LL, LH/HL, HH situations does the actual status corresponds [4].…”