Encoded digital video content protection between transport demultiplexer and decoder
View Patent ↗A system for encrypting and decrypting data is provided. The system includes a client for receiving a data packet, setting a value of a crypto bit, and transmitting the data packet over a system bus. A crypto module receives the data packet from the system bus and performs a cryptology function on the data packet based on a first value of the crypto bit. A memory controller receives the data packet from the system bus and performs non-cryptology functions on the data packet based on a second value of the crypto bit.
1. A system for encrypting and decrypting data comprising:
a client for receiving a data packet, setting a value of a crypto bit, and transmitting the data packet over a system bus;
a crypto module for receiving the data packet from the system bus and performing a cryptology function on the data packet based on a first value of the crypto bit; and
a memory controller for receiving the data packet from the system bus and performing non-cryptology functions on the data packet based on a second value of the crypto bit;
wherein the cryptology function comprises:
performing initial processing including reading the data packet and determining whether or not the data packet should be encrypted or decrypted;
modifying an encryption/decryption key using an address and a content ID of the data packet as well as a hashing algorithm; and
applying the modified key to the data packet to encrypt or decrypt data within the data packet.
2. The system of claim 1 wherein the crypto module further comprises a key generator for receiving a random number key and modifying the random number key based on predetermined fields of the data packet.
3. The system of claim 2 wherein the crypto module further comprises a bus slave module for controlling read and write operations between the system bus and the crypto module in response to client data.
4. The system of claim 3 wherein the crypto module further comprises a bus master module for controlling read and write operations between the system bus and the crypto module in response to data generated by the crypto module.
5. The system of claim 4 wherein the crypto module further comprises a read/write arbiter for determining a priority between read operations and write operations of the crypto module.
6. The system of claim 1 wherein the client comprises one or more of a transport stream processor, an audio decoder and a video decoder.
7. The system of claim 2 further comprising a transport stream processor for assigning a content ID for the data packet, wherein the key generator modifies the random number key based on the content ID of the data packet.
8. A method for encrypting and decrypting data comprising:
setting a crypto bit of a data packet to control encryption and decryption of the data packet;
transmitting the data packet over a system bus;
performing a proxy determination to determine if the data packet will be processed by a dedicated crypto module or by a memory controller as a function of the crypto bit;
processing the data packet with the dedicated crypto module based on a first value of the crypto bit; and
processing the data packet with the memory controller based on a second value of the crypto bit;
wherein the processing at the crypto module includes a cryptology function comprising:
performing initial processing including reading the data packet and determining whether or not the data packet should be encrypted or decrypted;
modifying an encryption/decryption key using an address and a content ID of the data packet as well as a hashing algorithm; and
applying the modified key to the data packet to encrypt or decrypt data within the data packet;
wherein both the crypto module and the memory controller receive but do not process data packets having an incorrect setting of the crypto bit.
9. The method of claim 8 wherein processing the data packet with the dedicated crypto module based on the first value of the crypto bit comprises reading or writing the data packet from or to the system bus using a bus interface slave module based on data received from a client.
10. The method of claim 9 wherein processing the data packet with the dedicated crypto module based on the first value of the crypto bit comprises reading or writing the data packet from or to the system bus using a bus interface master module based on data generated by the crypto module.
11. The method of claim 10 wherein processing the data packet with the dedicated crypto module based on the first value of the crypto bit comprises encrypting the data packet using a key modified using predetermined data attributes of the data packet.
12. The method of claim 11 wherein processing the data packet with the dedicated crypto module based on the first value of the crypto bit comprises decrypting the data packet using a key modified using predetermined data attributes of the data packet.
13. A system for encrypting and decrypting data comprising:
a client for receiving a data packet, setting a value of a crypto bit, and transmitting the data packet over a system bus;
at least one component that receives the data packet from the system bus and performs a cryptology function on the data packet based on a first value of the crypto bit; and
a memory controller for receiving the data packet from the system bus and performing non-cryptology functions on the data packet based on a second value of the crypto bit;
wherein the cryptology function comprises:
performing initial processing including reading the data packet and determining whether or not the data packet should be encrypted or decrypted;
modifying an encryption/decryption key using an address and a content ID of the data packet as well as a hashing algorithm; and
applying the modified key to the data packet to encrypt or decrypt data within the data packet.
14. The system of claim 13 wherein the at least one component receives a random number key and modifies the random number key based on predetermined data attributes of the data packet.
15. The system of claim 13 wherein the at least one component controls read and write operations between the system bus and the crypto module in response to client data.
16. The system of claim 13 wherein the at least one component controls read and write operations between the system bus and the crypto module in response to data generated by the crypto module.
17. The system of claim 13 wherein the at least one component determines a priority between read operations and write operations of the crypto module.
18. The system of claim 13 wherein the client comprises one or more of a transport stream processor, an audio decoder and a video decoder.
19. The system of claim 14 further comprising a transport stream processor for assigning a content ID for the data packet, wherein the at least one component modifies the random number key based on the content ID of the data packet.
20. The system of claim 13 wherein the at least one component generates a random number key and modifies the random number key based on predetermined data attributes of the data packet.