| 摘要 |
<p>The invention relates to a crypt key system applicable to a television system, a database system or an electronic commercial transaction system or the like. This system consists of a broadcasting station 11, a database 12, a receiving apparatus 14, a data communication apparatus 15 and a user terminal 18. As a crypt key system, a secret-key cryptosystem, a public-key cryptosystem, and a digital signature system are used. The keys used in the system are either encrypted or remain uncrypted to be supplied by broadcasting. The present invention is effective in the prevention of an unjustified use of the database system, managing copyrights, and in a pay-per-view system and a video-on-demand system. Further, the present invention is effective in realizing an electronic market which uses an electronic data information system.</p> |
