Method and apparatus for providing bus-encrypted copy protection key to an unsecured bus
First Claim
1. A method for providing a bus-encrypted copy protection (CP) key to an unsecured bus, the method comprising steps of:
- exchanging, between a first processor and a second processor, public keys that are shorter in length than public keys used to originally generate a copy protection key, over the unsecured bus to develop a shared secret bus encryption key, the shared secret bus encryption key having a first length;
generating, by the first processor, the CP key;
encrypting, by the first processor, the CP key using the shared secret bus encryption key and a symmetric encryption algorithm to produce a bus-encrypted CP key; and
providing the bus-encrypted CP key to the unsecured bus for the second processor.
2 Assignments
0 Petitions
Accused Products
Abstract
A copy protection (CP) key used by a sending source, such as a POD, to encrypt content such as audio and/or video information is derived by a first key generator associated with a first processor and is locally encrypted by the first processor using a locally generated bus encryption key to produce a bus encrypted CP key that is sent over a local unsecure bus to a second processor, such as a graphics processor. The second processor decrypts the bus encrypted copy key using a decryption engine to obtain the CP key. The second processor receives the encrypted content and in one embodiment, also uses the same decryption engine to decrypt the encrypted content. The first and second processors locally exchange public keys to each locally derive a bus encryption key used to encrypt the CP key before it is sent over the unsecure bus and decrypt the encrypted CP key after it is sent over the bus. The locally exchanged public keys are shorter in length than those used between the CPU and POD to produce the original CP key.
125 Citations
18 Claims
-
1. A method for providing a bus-encrypted copy protection (CP) key to an unsecured bus, the method comprising steps of:
-
exchanging, between a first processor and a second processor, public keys that are shorter in length than public keys used to originally generate a copy protection key, over the unsecured bus to develop a shared secret bus encryption key, the shared secret bus encryption key having a first length;
generating, by the first processor, the CP key;
encrypting, by the first processor, the CP key using the shared secret bus encryption key and a symmetric encryption algorithm to produce a bus-encrypted CP key; and
providing the bus-encrypted CP key to the unsecured bus for the second processor. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. An integrated circuit adapted to receive a transport stream having a plurality of encrypted packets that have been encrypted using a copy protection key (CP) and having a port to couple to an unsecure bus, the integrated circuit comprising:
a decryption module including;
a bus encryption key generator; and
a decryptor operatively responsive to a bus-encrypted CP key and having a first selector operative to select between the transport stream and the bus-encrypted copy protection key, and operative to decrypt selected encrypted packets based on a decrypted bus-encrypted CP key. - View Dependent Claims (8, 9, 10, 11, 12, 13, 15, 16, 17, 18)
-
14. A system for providing a bus-encrypted copy protection (CP) key to an unsecured bus, the system comprising:
-
a first processor operatively coupled to a second processor via an unsecure bus, having a first bus encryption key generator and a CP key encryptor operatively responsive to a shared secret bus encryption key produced by the first bus encryption key generator;
the second processor having a second bus encryption key generator; and
a decryptor operatively responsive to a bus-encrypted CP key and having a first selector operative to select between a transport stream and the bus-encrypted copy protection key, and operative to decrypt selected encrypted packets based on a decrypted bus-encrypted CP key.
-
Specification