| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a mechanism for content lending in a group while considering copyright problems. <P>SOLUTION: A private key 15 records decoding/encoding information 51, added information 53 including copy count restriction information 53a, valid period restriction information 53b, view restrictions 53c and key division permission information 53d, and an electronic signature 55. The added information 53 is information set under license from a copyrighter. The use of the private key 15 can impose use restrictions on content. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
