Patent ID: 8265269

Claim:
A receiving apparatus, comprising: a receiving unit configured to receive a digital broadcast signal including a scrambled broadcast signal, information for generating a device key, an encrypted work key, and an encrypted scrambling key, in a transport stream format; a device key generating unit configured to generate a device key by obtaining the information for generating the device key from the transport stream and applying a device key generation procedure that has been stored in advance in the receiving apparatus; a work key generating unit configured to obtain the encrypted work key from the transport stream, decrypt the encrypted work key using the device key generated by the device key generating unit, and generate a work key; a scrambling key generating unit configured to obtain the encrypted scrambling key from the transport stream, decrypt the encrypted scrambling key using the work key generated by the work key generating unit, and generate a scrambling key; a descrambling unit configured to descramble the scrambled broadcast signal using the scrambling key generated by the scrambling key generating unit; a device key storing unit configured to sequentially store the device key generated by the device key generating unit, every time the device key is updated; and a recording unit configured to store the digital broadcast signal in the transport stream format, wherein in a case where the device key generating unit cannot generate, from the stored transport stream, a device key necessary for descrambling the stored transport stream when the transport stream stored by the recording unit is to be reproduced, the work key generating unit decrypts the encrypted work key that is obtained from the stored transport stream, using the device key stored in the device key storing unit, and generates a work key.