The present invention provides methods and systems for identifying content
to help ensure legal uses of the content. In one implementation a method
is provided to include obtaining content, wherein the content comprises a
steganographic signal hidden therein through subtle changes to data
representing the content; accessing a registry including a plurality of
steganographic decoding keys to obtain a key associated with the content,
wherein at least some of the keys are encrypted; obtaining the key
associated with the content; and decoding the steganographic signal
hidden in the content utilizes at least the key associated with the
content.