A most critical and complex issue with regard to constrained devices in the ubiquitous and pervasive computing setting is secure key exchange. The restrictions motivate the investigation and discussion of alternative solutions. We suggest a low hardware-complexity solution for authenticated symmetric key exchange, using a Tree Parity Machine Rekeying Architecture. An authenticated key exchange is formulated from within the tree parity machine interaction concept and requires only few transmissions. It averts a Man-In-The-Middleattack and the currently known attacks on the non-numbertheoretic on principle. A key exchange can be performed within a few milliseconds, given typical limited bandwidth wireless communication channels. A flexible rekeying functionality enables the exploitation of the achievable key exchange rates. Characteristics of a standard-cell ASIC design realization as IP-core in ¢¡¤£¦¥¨§ -CMOS technology are evaluated.