Patent ID: 7522728

Claim:
A method of operating a cell phone, comprising: receiving auxiliary data wirelessly sent to the cell phone from a remote transmitter; thereafter, receiving input information and expressing the input information in digital form; steganographically encoding the input information to hide a plural-bit auxiliary code therein, the encoding depending, at least in part, on the received auxiliary data sent to the cell phone from the remote transmitter; and transmitting the steganographically-encoded information from the cell phone by wireless in a digital format; wherein: the input information is digitally marked with the plural-bit auxiliary code prior to being transmitted, but such code is hidden due to its steganographic nature; the plural-bit auxiliary code is retrievable only by entities that (1) receive the information sent by the cell phone; (2) know that a code is present despite being hidden, and (3) have information about its manner of encoding; and the method thereby provides a hidden channel through which a code dependent on auxiliary data earlier sent to a cell phone can be transmitted from the cell phone.