Patent ID: 8428556

Claim:
A communication terminal device which performs talks and communications via a communication network, the terminal device comprising: a communication history information memory device which stores history information of the talks and communications by each talk and communication partner user; a condition information memory device which stores a reliability rule that is a basis for judging a reliability relationship of the talks and communications; a communication admissible list generating device which judges whether or not the partner user is reliable enough based on the history information of the talks and communications stored in the communication history information memory device by each partner user of the talks and communications and the reliability rule stored in the condition information memory device, and generates a list with a valid time limit; a communication admissible list memory device which stores the list generated by the communication admissible list generating device, and provides the list in response to an inquiry that is made when performing the talk and communication with the partner user; and a communication device which makes an access to the communication admissible list memory device to search the list of a partner user with which a talk and a communication is to be performed, judges reliability of the partner user based on a search result thereof, and controls the talk and communication.