SYSTEM AND METHOD FOR LAWFUL INTERCEPTION USING TRUSTED THIRD PARTIES IN VOIP SECURE COMMUNICATIONS

摘要

A legal wiretapping system for VoIP(Voice over Internet Protocol) security communication by using the third trusted party and a legal wiretapping method therefor are provided to offer perfect legal wiretapping under VoIP security communication environment, and to change a master key managed by the third trusted party whenever calls are made, thereby ensuring perfect forward secrecy. A third trusted party(10) generates a master key by receiving a master key request from a VoIP sending terminal(20), and transmits the master key to the sending terminal and a key recovery processing system(50). The key recovery processing system transmits a legal wiretapping command to a collecting device(30), receives security packets as well as the master key, and decodes the security packets by using the master key to provide the decoded packets to a legal wiretapping requester(60), or provides the master key and the security packets to the requester. The collecting device collects the security packets transceived between the sending terminal and a VoIP receiving terminal(40), and sends the collected security packets to the key recovery processing system.