The necessity to secure the communication between hardware components in
embedded systems becomes increasingly important with regard to the secrecy of
data and particularly its commercial use. We suggest a low-cost (i.e. small
logic-area) solution for flexible security levels and short key lifetimes. The
basis is an approach for symmetric key exchange using the synchronisation of
Tree Parity Machines. Fast successive key generation enables a key exchange
within a few milliseconds, given realistic communication channels with a
limited bandwidth. For demonstration we evaluate characteristics of a
standard-cell ASIC design realisation as IP-core in 0.18-micrometer
CMOS-technology