Patent ID: 8595502

Claim:
A method comprising: a computing device requesting data content from a data management center; subsequent to said requesting data content, the computing device receiving from the data management center: an encrypted version of a first message, wherein the first message comprises the requested data content and a first electronic watermark that includes information relating to a first user of the computing device; and an encrypted first secret key; the computing device decrypting the received encrypted version of the first message; the computing device decrypting the received encrypted first secret key using a user key; the computing device encrypting a second message using the decrypted first secret key, wherein the second message comprises the requested data content, the first electronic watermark, and a second electronic watermark that includes information relating to a second user that is different from the first user; and the computing device sending information to the data management center that is usable by the data management center to confirm that the second user is allowed to receive the first secret key to decrypt the second message.