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Very recently, it has been shown that Gaussian thermal noise and its artificial versions (Johnson-like noises) can be
utilized as an information carrier with peculiar properties therefore it may be proper to call this topic Thermal Noise
Informatics. Zero Power (Stealth) Communication, Thermal Noise Driven Computing, and Totally Secure Classical
Communication are relevant examples. In this paper, while we will briefly describe the first and the second subjects, we
shall focus on the third subject, the secure classical communication via wire. This way of secure telecommunication
utilizes the properties of Johnson(-like) noise and those of a simple Kirchhoff's loop. The communicator is
unconditionally secure at the conceptual (circuit theoretical) level and this property is (so far) unique in communication
systems based on classical physics. The communicator is superior to quantum alternatives in all known aspects, except
the need of using a wire. In the idealized system, the eavesdropper can extract zero bit of information without getting
uncovered. The scheme is naturally protected against the man-in-the-middle attack. The communication can take place
also via currently used power lines or phone (wire) lines and it is not only a point-to-point communication like quantum
channels but network-ready. We report that 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 with ranges
beyond the ranges of any known direct quantum communication channel and they indicate unrivalled signal fidelity and
security performance. This simple device has single-wire secure key generation/sharing rates of 0.1, 1, 10, and 100
bit/second for copper wires with 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 setting on 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
Bergou-Scheuer-Yariv type give an upper limit of eavesdropped raw bit ratio is 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.
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