Abstract
When a mobile node roams, its location information can be revealed from the IP prefix information of its care-of address. This paper proposes a protocol to hide the relationship between home address and care-of address of a mobile node. In the protocol, any two real addresses regarding route optimization will never be included in a traffic packet. Hence the movement of a mobile node can be hidden from third party monitoring. The protocol changes neither the format of the binding update nor the format of IP packets in Mobile IPv6.