| 摘要 |
A first device transfers to a second device content that is encrypted with a content key. The second device requests access to the content from an authorized agent. Upon a determination that any conditions for approving such a request are satisfied, the authorized agent decrypts a superdistribution key with its private key, and encrypts the resultant content key with the public key of the second device. This encryption produces a protected content key, which is sent to the second device. Upon receipt of this protected content key, the second device will be able to access the content by decrypting the protected content key with the private key of the second device. At this point, the second device may decrypt the content with the content key. |
