Blockchain-based digital rights management

1. A method for generating a rights blockchain storing rights of a user, the method comprising:

receiving, at a registration authority, an enrollment request and a public key from the user;

verifying, at the registration authority, that the user has a private key corresponding to the public key;

generating, at the registration authority, a user identifier using the public key;

generating and delivering, at the registration authority, the rights blockchain having a genesis block including the user identifier to the user; and

updating, at the registration authority, the rights blockchain including a new block having a content identifier of a protected content, associated usage rights, a hash of the new block, and a hash of a block subsequent to the new block,

wherein the protected content includes the content identifier, a scrambled essence, and a control word, which is a random number generated by a content provider,

wherein the scrambled essence is descrambled using the control word.

2. The method of claim 1 , further comprising

requesting a different public key when the public key is already registered.

3. The method of claim 1 , further comprising

receiving information from the content provider that the user has acquired the protected content having the content identifier.

4. The method of claim 1 , wherein the associated usage rights include

a list of licensed languages and subtitle languages.

5. An apparatus for generating a rights blockchain storing rights of a user, the apparatus comprising:

means for receiving an enrollment request and a public key from the user,

means for verifying that the user has a private key corresponding to the public key,

means for generating a user identifier using the public key,

means for generating and delivering the rights blockchain having a genesis block including the user identifier to the user, and

means for updating the rights blockchain including a new block having a content identifier of a protected content, associated usage rights, a hash of the new block, and a hash of a block subsequent to the new block,

wherein the protected content includes the content identifier, a scrambled essence, and a control word, which is a random number generated by a content provider, wherein the scrambled essence is descrambled using the control word.

6. The apparatus of claim 5 , further comprising

wherein the content provider informs a registration authority that the user has acquired a content.

7. The apparatus of claim 6 , further comprising

means for receiving and updating the rights blockchain with a new block having a content identifier of the content and associated usage rights.

8. The apparatus of claim 7 , wherein the content provider is also configured to scramble the content corresponding to the content identifier in the updated rights blockchain and to generate a scrambled version of the content.

9. A method for performing digital rights management of a content using a rights blockchain storing rights of a user, the method comprising:

receiving, at a DRM agent, a protected content including a content identifier, a scrambled essence, and an encrypted control word, which is a random number generated by a content provider,

wherein the scrambled essence is an essence of the content scrambled using the encrypted control word to protect it from unauthorized uses;

receiving, at the DRM agent, the rights blockchain and credentials of the user;

searching, at the DRM agent, the rights blockchain for a first block that contains the content identifier of the protected content;

decrypting, at the DRM agent, the encrypted control word when a signature and usage rights in the first block are determined to be valid; and

descrambling, at the DRM agent, the scrambled essence using the decrypted control word to produce the essence of the content.

10. The method of claim 9 , further comprising:

performing, at the DRM agent, an integrity check of the rights blockchain to determine that the rights blockchain has not been compromised or tampered with.

11. The method of claim 9 , wherein the rights blockchain includes a genesis block having a user identifier of the user, and the credentials of the user are cryptographically linked to the user identifier.

12. The method of claim 9 , further comprising

determining, at the DRM agent, whether the signature and the usage rights of the first block are valid.

13. A method for generating a rights blockchain storing rights of a user to consume an item of content, the method comprising:

receiving, at a registration authority, an enrollment request and a public key from the user and verifying that the user has a private key corresponding to the public key;

generating, at a registration authority, a genesis block including a user identifier of the user using the public key; and

generating and adding, at a registration authority, a new block having a content identifier of the item of content, associated usage rights, a hash of the new block, and a hash of a block subsequent to the new block,

wherein the item of content also includes a content identifier, a scrambled essence, and a control word, which is a random number generated by a content provider, and

wherein the scrambled essence is descrambled using the control word.