To provide a data broadcasting system for distributing the contents of data broadcasting by preventing the contents from being acquired illegally.

A broadcasting facility side 1 is provided with a contents enciphering means 12 for enciphering contents with a charging key and a charging key enciphering means 15 for enciphering the charging key. A receiver 2 is provided with a data broadcasting protocol interpreting means 21 for extracting the contents enciphered with the charging key, and a security module 3 of the receiver is provided with a transfer enciphering means 35 for enciphering the decoded charging key with a transfer key. The contents enciphered with charging key and the charging key enciphered with the transfer key are transferred from the receiver to external equipment 4. The external equipment is provided with a transfer key generating means 41, a charging key decoding means 42 for decoding the charging key enciphered with the transfer key and a contents decoding means 43 for decoding the enciphered contents with charging key. Thus, it is not necessary to extract raw contents with the receiver. Therefore, high security can be maintained, and to prevent illegal acquiring of the contents.