Access to encrypted broadcast content

Apparatus for providing access to a broadcast content item, the apparatus comprising:

• a receiver subsystem having a public private key pair;
• a content provider subsystem having an first encryption unit for encrypting the broadcast content item based on a content key to produce an encrypted content item, a nonce generator for, generating a blocking nonce corresponding to the content key, and a first transmitter connected to the encryption unit and nonce generator for transmitting the content key, the blocking nonce—and the encrypted content item;
• and,
• a clearing house subsystem having a first receiver for receiving the content key and the blocking nonce from the content provider subsystem and the public key of the receiver subsystem, a second encryption unit connected to the first receiver for encrypting the content key based on the public key to produce a public key encrypted content key and encrypting the public key encrypted content key based on the blocking nonce to produce a double encrypted content key in response to a request for access to the broadcast content item, and a second transmitter connected to the second encryption unit for transmitting the double encrypted content key to the receiver subsystem;
• wherein, the receiver subsystem further comprises a second receiver for receiving the double encrypted content key from the clearing house subsystem and the encrypted content item and the blocking nonce from the content provider subsystem, and a decryption unit connected to the receiver for decrypting the double encrypted content key based on the blocking nonce to recover the public key encrypted content key, decrypting the public key encrypted content key based on a private key of the public private key pair to recover the content key, and decrypting the encrypted content item based on the content key to recover the requested broadcast content item.

An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing provision of a receiver subsystem with access via a clearing house subsystem to the broadcast content item broadcast from a content provider subsystem, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect:

• in the content provider subsystem, encrypting the broadcast content item based on a content key to produce an encrypted content item, generating a blocking nonce corresponding to the content key, transmitting the content key and the blocking nonce to the clearing house subsystem, and transmitting the encrypted content item and the blocking nonce to the receiver subsystem;
• in the clearing house subsystem, receiving the content key and the blocking nonce from the content provider subsystem, receiving a public key of a public-private key pair of the receiver subsystem, and, in response to a request for access to the broadcast content item, encrypting the content key based on the public key to produce a public key encrypted content key, encrypting the public key encrypted content key based on the blocking nonce to produce a double encrypted content key, and transmitting the double encrypted content key to the receiver subsystem;
• and,
• in the receiver subsystem, receiving the double encrypted content key from the clearing house subsystem, receiving the encrypted content item and the blocking nonce from the content provider subsystem, decrypting the double encrypted content key based on the blocking nonce to recover the public key encrypted content key, decrypting the public key encrypted content key based on a private key of the public-private key pair to recover the content key, and decrypting the encrypted content item based on the content key to recover the requested broadcast content item.

A computer program product comprising a computer usable medium having computer readable program code means embodied therein for causing provision of a broadcast content item, the computer readable program code means in said computer program product comprising computer readable program code means for causing a computer to effect:

• a receiver subsystem having a public private key pair;
• a content provider subsystem having an first encryption unit for encrypting the broadcast content item based on a content key to produce an encrypted content item, a nonce generator for generating a blocking nonce corresponding to the content key, and a first transmitter connected to the encryption unit and nonce generator for transmitting the content key, the blocking nonce and the encrypted content item;
• and,
• a clearing house subsystem having a first receiver for receiving the content key and the blocking nonce from the content provider subsystem and the public key of the receiver subsystem, a second encryption unit connected to the first receiver for encrypting the content key based on the public key to produce a public key encrypted content key and encrypting the public key encrypted content key based on the blocking nonce to produce a double encrypted content key in response to a request for access to the broadcast content item, and a second transmitter connected to the second encryption unit for transmitting the double encrypted content key to the receiver subsystem;
• wherein, the receiver subsystem further comprises a second receiver for receiving the double encrypted content key from the clearing house subsystem and the encrypted content item and the blocking nonce from the content provider subsystem, and a decryption unit connected to the receiver for decrypting the double encrypted content key based on the blocking nonce to recover the public key encrypted content key, decrypting the public key encrypted content key based on a private key of the public private key pair to recover the content key, and decrypting the encrypted content item based on the content key to recover the requested broadcast content item.