  We show how to extract messages masked by a chaotic signal of a time-delay
system with very high dimension and many positive Lyapunov exponents. Using a
special embedding coordinate, the infinite dimensional phase space of the
time-delay system is projected to a special three-dimensional space, which
enables us to identify the time-delay of the system from the transmitted
signal, and reconstruct the chaotic dynamics to unmask the hidden message
successfully. The message extraction procedure is illustrated by simulations
with Mackey-Glass time-delay system for two type of masking schemes and
different kinds of messages.
