Patent ID: 8918636

Claim:
A source encoder, comprising: a processor; non-volatile storage containing an encoding application for encoding and protecting frames of video to create a plurality of alternative streams of protected content; wherein the encoding application configures the processor to: receive a source content; obtain a common set of frame keys comprising a plurality of frame keys; encode the source content as a plurality of streams including a plurality of alternative streams of content, wherein each alternative stream of content comprises a plurality of encoded video frames; encrypt portions of several encoded video frames from each alternative stream of content using keys from the same common set of frame keys; after encrypting the portions of encoded video frames, write the encoded video frames of each alternative stream of protected content to a separate container file from a plurality of container files and, for each encoded video frame with an encrypted portion that is written to a given container file, write a DRM information to the given container file that identifies (i) an encrypted portion of the encoded video frame and (ii) a frame key from the common set of frame keys that can be utilized by a playback device to access the encrypted portion of the encoded video frame; and store an encrypted copy of the common set of frame keys in each container file, wherein each encrypted copy of the common set of frame keys has been encrypted with at least one encryption key.