| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a transmitter and a receiver capable of easily changing a content to a stream encryption system on the basis of a conventional Conditional Access System (CAS). <P>SOLUTION: A transmitter using a conditional access system for digital broadcasting using a broadcast wave or a communication line, includes: a stream encryption section 11 for setting a fixed value as an initial value used for initialization of a stream encryption algorithm, initializing the stream encryption algorithm by using the initial value, and performing stream encryption for a content by using a scramble key; a first encryption section 12 for encrypting the initial value and the scramble key by using a work key; a second encryption section 13 for encrypting the work key by using a master key common between the transmitter and a receiver; and transmitting means for transmitting stream encrypted data obtained by performing the stream encryption by the stream encryption section, encrypted data of the initial value, encrypted data of the scramble key, and encrypted data of the work key by using the broadcast wave or the communication line. <P>COPYRIGHT: (C)2012,JPO&INPIT |
