Patent ID: 7447909

Claim:
A method for lawful interception of packet switched network services, comprising the steps of: when a user accesses the network and is identified by a target-ID at a primary interception point of the network, sending the target-ID to an interception management center, checking at the interception management center whether the user is a lawful interception target and sending an encrypted interception instruction set to a secondary interception point, decrypting said interception instruction set at the secondary interception point and performing an interception process in accordance with the interception instruction set, said interception process including the transmission of encrypted interception and dummy data to a mediation device, wherein said dummy data are added for obscuring true interception traffic between the secondary interception point and the mediation device, and wherein an amount of the dummy data is determined based on actual traffic load, wherein the interception instruction set includes a conditional interception instruction, instructing a PSSP (Packet Switching Service Point) to send intercept related information or to monitor the traffic associated with the target-ID and start the interception of the complete traffic or a portion of the traffic only when a certain trigger condition occurs, said trigger condition being one of: usage of certain network or content resources or usage of a certain catchword, virus signature or bit-pattern specified in the interception instruction set.