ACCESS TO ENCRYPTED BROADCAST CONTENT

摘要

A method is disclosed for providing a receiver subsystem with access via a clearing house subsystem to a content item broadcast from a content provider subsystem. In the content provider subsystem, the content item is encrypted based on a content key to produce an encrypted content item, a blocking nonce is generated corresponding to the content key, the content key and blocking nonce are transmitted to the clearing house subsystem, and the encrypted content item and blocking nonce are transmitted to the receiver subsystem. In the clearing house subsystem, the content key and blocking nonce are received from the content provider subsystem, a public key of a public-private key pair of the receiver subsystem is received, and, in response to a request for access to the content item, the content key is encrypted based on the public key to produce a public key encrypted content key, the public key encrypted content key is encrypted based on the blocking nonce to produce a double encrypted content key, and the double encrypted content key is transmitted to the receiver subsystem. In the receiver subsystem, the double encrypted content key is received from the clearing house subsystem, the encrypted content item and blocking nonce are received from the content provider subsystem, the double encrypted content key is decrypted based on the blocking nonce to recover the public key encrypted content key, the public key encrypted content key is decrypted based on a private key of the public-private key pair to recover the content key, and the encrypted content item is decrypted based on the content key to recover the requested content item.