A source generates a medium key (KM) and a media secret table including a
plurality of entries, each entry including (KM) encrypted by a public key
(PU-PD) of a plurality of devices, obtains the medium ID of a medium
therefrom, generates a content key (KD) for a piece of content, encrypts
the content with (KD) to result in (KD(content)), encrypts (KD) with (KM)
to result in (KM(KD)), generates a package for the content including
(KD(content)), (KM(KD)), the medium ID, and a signature based on at least
the medium ID and verifiable with (KM), and copies the generated package
and the media secret table to the medium. Thus, a device with the medium
and a private key (PR-PD) corresponding to an entry of the media secret
table can access and render the content.
