System and method for encrypting and decrypting data

1. A method of creating an encrypted data file from a data file having a sample entry box and a media data box, the sample entry box having description information therein, the media data box including media data therein, said method comprising:

receiving the data file;

encrypting the media data within the media data box with an encryption key;

replacing the sample entry box with an encoded box;

creating a sinfbox within the encoded box;

creating a form a box within the sinfbox; and

creating an schm box within the sinfbox,

wherein the schm box indicates the type of formatting of the encrypted media data,

wherein the encoded box does not include an initial counter or initial vector that may be used to decrypt the encrypted media data; and

wherein the initial counter is encoded with the description information, and not the media data box.

2. The method of claim 1 , wherein said creating a sinfbox within the encoded box includes creating only a form a box and a schm box within the sinfbox.

3. A method of creating a data file from an encrypted data file, an encrypted key seed and intellectual property rights data, the encrypted data file having an encoded box and an encrypted media data box, the encoded box having a sinfbox therein, the sinfbox having therein a form a box and a schm box, the encrypted media data box having encrypted media data therein, the schm box indicating the type of formatting of the encrypted data file, said method comprising:

receiving the encrypted data file;

receiving the encrypted key seed in the encoded box, and not in the media data box;

receiving the encrypted intellectual property rights data;

determining the encryption scheme from the schm box;

deriving a content decryption key based on the encrypted key seed and the intellectual property rights data;

deriving an initial counter based on the encrypted key seed and data within the encrypted data file;

decrypting, via the initial counter and the content decryption key, the encrypted media data within the encrypted media data box; and

replacing the encoded box with a sample entry box.

4. The method of claim 3 , further comprising creating a free box within the sample entry box.

5. A device for use with an encoder and with an intellectual property rights management device, the encoder being operable to provide a media data file and a file offset, the intellectual property rights management device having therein pre-determined data and intellectual property rights data and being operable to provide an encryption key seed, the media data file having media data therein, said device comprising:

a processor; and

a memory connected to the processor, the memory storing code to executed by the processor to enable the processor to provide the following processing portions:

an encrypting portion arranged to receive the media data;

a salting key derivation portion operable to derive a salting key based on the encryption key seed;

an content encryption key derivation portion operable to derive an content encryption key based on the encryption key seed; and

an initial counter generating portion operable to generate an initial counter based on the salting key and the file offset,

wherein said encrypting portion is further operable to encrypt the media data based on the initial counter and the content encryption key; and

wherein the predefined data includes the data reference to the media data file for the media data in a different media file.

6. The device of claim 5 , wherein said salting key derivation portion is operable to derive the salting key based additionally on the predefined data.

7. The device of claim 5 , wherein said content encryption key derivation portion is operable to derive the content encryption key based additionally on the intellectual property rights data.

8. The device of claim 6 , wherein said content encryption key derivation portion is operable to derive the content encryption key based additionally on the intellectual property rights data.

9. The device of claim 5 , wherein said content encryption key derivation portion is operable to derive the content encryption key based additionally on the intellectual property rights data.

10. A device for use with a receiver and with an intellectual property rights management device, the receiver being operable to provide an encrypted media data file and a file offset, the intellectual property rights management device having therein predetermined data and intellectual property rights data and being operable to provide an encryption key seed, the encrypted media data file having encrypted media data therein, said device comprising:

a processor; and

a memory connected to the processor, the memory storing code to executed by the processor to enable the processor to provide the following processing portions:

a decrypting portion arranged to receive the encrypted media data;

a salting key derivation portion operable to derive a salting key based on the encryption key seed;

a content encryption key derivation portion operable to derive a content encryption key based on the encryption key seed; and

an initial counter generating portion operable to generate an initial counter based on the salting key and the file offset,

wherein said decrypting portion is further operable to decrypt the encrypted media data based on the initial counter and the content encryption key; and

wherein the predefined data includes the data reference to the media data file for the media data in a different media file.

11. The device of claim 10 , wherein said salting key derivation portion is operable to derive the salting key based additionally on the predefined data.

12. The device of claim 11 , wherein said content encryption key derivation portion is operable to derive the content encryption key based additionally on the intellectual property rights data.

13. The device of claim 10 , wherein said content encryption key derivation portion is operable to derive the content encryption key based additionally on the intellectual property rights data.