The present invention related generally to audio encoding and decoding. Various arrangements are disclosed. One method obtains audio, wherein authorized or original audio comprises in-band information and associated out-of-band information; searches for out-of-band information associated with obtained audio; searches the obtain audio for in-band information associated with the obtained audio; and based at least in part on a result of the searching for out-of-band information and the searching the obtained audio for in-band information, reaches a decision regarding the obtained audio. Other arrangements are disclosed as well.