| 摘要 |
PURPOSE:To avoid information from being received illegally even if the information is served to lots of unspecified recipients by providing a CD-ROM storing identical data to both sender and receiver sides. CONSTITUTION:Information A from an information source 1 is coded by using a code data B from a CD-ROM 2 storing plural code data such as pass words and sent from a sender side. A receiver 5 at a receiver side receives the data, separates it into coded information C and a retrieval data D, the information C is supplied to a demodulator 7 and the retrieval data D is supplied to a CD- ROM6. Since the same code data in those of the sender ROM 2 are stored in the ROM 6 with the same address, the same code data B is read by the address data of the retrieval data D to demodulate the information C. Thus, only a person having the same ROM as the ROM of the sender side can receive the information. |
