Copyright informations at the age of net can be easily falsified or deleted,which would cause damages to right owner,hence it s indispensable to give them mighty protection.

And finally the writer proposed some copyright management countermeasures to the P2P file sharing techniques.

This paper expounds the principles, features and particularity of the copyright management in digital library, and introduces the application and protection of digital copyright management.

This paper points out that under the network environment the construction of the digital library is closely linked with the copyright protection,which include the digitalized transformation of the resources,the right of the network transmission,the technical privacy protection,and the copyright management information,etc.

Meanwhile it goes further into the problem by discussing construction of librarian team,control over readers,management of copyright,protection in techniques,and finally the countermeasures are given.

Research of trust management model for distributing condition;

Analysis of P2P trust management based on functions;

D1LP-R based trust management frameworkin multi-agent systems;