  It has been shown recently that the use of two pairs of resistors with
enhanced Johnson-noise and a Kirchhoff-loop-i.e., a Kirchhoff-Law-Johnson-Noise
(KLJN) protocol-for secure key distribution leads to information theoretic
security levels superior to those of a quantum key distribution, including a
natural immunity against a man-in-the-middle attack. This issue is becoming
particularly timely because of the recent full cracks of practical quantum
communicators, as shown in numerous peer-reviewed publications. This
presentation first briefly surveys the KLJN system and then discusses related,
essential questions such as: what are perfect and imperfect security
characteristics of key distribution, and how can these two types of securities
be unconditional (or information theoretical)? Finally the presentation
contains a live demonstration.
