  In this paper we propose a multi-map orbit hopping chaotic stream cipher that
utilizes the idea of spread spectrum mechanism for secure digital
communications and fundamental chaos characteristics of mixing, unpredictable,
and extremely sensitive to initial conditions. The design, key and subkeys, and
detail implementation of the system are addressed. A variable number of well
studied chaotic maps form a map bank. And the key determines how the system
hops between multiple orbits, and it also determines the number of maps, the
number of orbits for each map, and the number of sample points for each orbits.
A detailed example is provided.
