  The statistical-physics-based Kirchhoff-law-Johnson-noise (KLJN) key exchange
offers a new and simple unclonable system for credit/debit card chip
authentication and payment. The key exchange, the authentication and the
communication are unconditionally secure so that neither mathematics- nor
statistics-based attacks are able to crack the scheme. The ohmic connection and
the short wiring lengths between the chips in the card and the terminal
constitute an ideal setting for the KLJN protocol, and even its simplest
versions offer unprecedented security and privacy for credit/debit card chips
and applications of physical unclonable functions.
