Patent ID: 7543148

Claim:
A method for concealing data within a digital audio signal, the method comprising: receiving, at a computing device including a process executing a watermark encoding system, a first data pattern of discrete values which are bits of a watermark and a second data pattern of discrete values which are bits of a covert message; imposing, at the computing device, a discrete value of the second data pattern over one or more discrete values of the first data pattern to generate a third data pattern, wherein the imposing is carried out by performing a Boolean operation with a discrete value of the second data pattern and multiple discrete values of the first data pattern; processing the digital audio signal into a series of bitframes at the computing device, wherein each bitframe includes a set of frames, and wherein each frame includes a set of blocks; and encoding the third data pattern into the digital audio signal at the computing device, wherein a different bit of the watermark is encoded in each frame of at least one subject bitframe, and wherein a same bit of the covert message is encoded in each frame of the subject bitframe, wherein the same bit of the covert message is encoded in each frame of the subject bitframe at a different frequency with respect to each frame.