Patent ID: 8719947

Claim:
A method for playing secure media content on a playback device, the method comprising: receiving encrypted media content from storage in the playback device, wherein the encrypted media content is parsable but not playable when decoded by a decoder conforming to a predetermined media standard; decrypting the encrypted media content; parsing the decrypted media content into portions, wherein only predetermined portions have been modified and the modification does not corrupt a structure of the modified portions; in each decrypted and parsed portion, detecting whether a value of at least one predetermined bit location matches a reserved value according to the predetermined media standard, so as to determine whether the portion has been modified; when the detected value does not match the reserved value: decoding the portion using the decoder; and playing the decoded portion; and when the detected value matches the reserved value: accessing a routine from a secure memory location in the playback device; decoding the modified portion using the routine; and playing the decoded portion.