Abstract: A system and method for safe communication in a complex scattering environment is achieved by means of providing a passive nonlinear object in the wave propagation environment which nonlinearly interacts with the waves to create an exclusive communication channel between the nonlinear object and any point where the waves can be collected. Excitations generated by the nonlinearity in the time-reversal mirror are gathered, time-reversed, and retransmitted into the environment. The retransmitted signals arrive and are reconstructed exclusively at the location of the nonlinear object or linear object depending on the linearity or nonlinearity of the retransmitted sonas. The principles of the system and method are useful in numerous applications where signal communication or power delivery is desired to an object whose location is not known or dynamically changed in an exclusive, highly localized, precise, and secure fashion.