| 摘要 |
<P>PROBLEM TO BE SOLVED: To exercise rights based on trust determined in issuance of a rights expression. <P>SOLUTION: Rights expressions are issued by a chain of servers, forming a chain of rights expressions issued from server to server and finally from the last server to a client, such that each of the rights expressions except the last includes a specification of rights for the next server to issue the rights in the next rights expression It is determined whether or not each of the servers has a right to issue the respective rights expressions. If it is determined that each of the servers had a right to issue the respective rights expression, the rights expressed in the last rights expression as being trusted are exercised by the client. If it is determined that at least one server did not have the right to issue the respective rights expression, the rights expressed in the last rights expression as not being trusted are not exercised by the client. <P>COPYRIGHT: (C)2009,JPO&INPIT |
