Patent ID: 8256005

Claim:
A method of playing secure video or audio data on a playback device, comprising the acts of: receiving encrypted audio or video data from storage in the device, the audio or video data in addition to being encrypted having only predetermined portions poisoned according to logic wherein the encrypted audio or video data are parsable but not playable when decoded by a standard decoder, wherein the standard decoder conforms to the AAC or H.264 standard and the poisoning does not corrupt the structure of the poisoned portions; decrypting the data; parsing the decrypted data into portions; in each decrypted and parsed portion, detecting the value of at least one predetermined bit location so as to determine whether that portion has been poisoned, wherein the value of the predetermined bit location is a reserved value according to the standard; when the detected value does not match a predetermined value, indicating the absence of the poisoning, decoding the portion using the standard decoder, and playing the decoded portion; when the detected value matches the predetermined value, indicating the presence of the poisoning in the decrypted and parsed portion, accessing a routine from a secure memory location in the playback device; and decoding the poisoned portion using the routine and playing the decoded portion.