Patent ID: 8181014

Claim:
A method of protecting the routing of data packets in a packet data network along a transmission path with routers between a first sending end-host and a second receiving end-host, comprising the following steps performed by a DNS server system: receiving an address query from the first end-host regarding the second end-host, retrieving a destination address associated with the second end-host for said address query, encrypting the retrieved destination address by using a key dependent on a master key wherein the master key has been distributed to said routers in the packet data network for encryption of destination addresses in data packets, and creating a destination parameter containing the encrypted destination address, sending the created destination parameter to the first end-host in response to said address query, thereby enabling the first end-host to get across data packets to the second end-host by attaching said destination parameter to each transmitted data packet, and enabling the routers to decrypt the encrypted destination address in the data packets from the first end-host using a key dependent on the distributed master key, and performing a forwarding operation based on the decrypted destination address and a new encrypted destination address being attached to a forwarded packet to determine an outgoing port for the packet.