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Methods, devices and computer program products for enabling secure and efficient extraction of embedded water marks from digital host content are provided. Upon the recep tion of a multi-channel digital host content with embedded watermarks, a Subset of the received channels are selected and combined together to form a composite content. The compos ite content is then examined to recover embedded water marks. The particular subset of channels can be selected according to a probability value. Further, a set of new chan nels can be selected and combined after a particular time interval has elapsed. The number of selected channels can also be varied each time a new selection is made.