An Attack on Untraceable Linear Network Coding
Christiane Kuhn, Friederike Kitzing, Thorsten Strufe · 2018
The privacy of users in wireless mesh networks is threatened by attackers that trace the flow of packets through the network or trace users' movements within the network. Untraceable Linear Network Coding, a scheme to provide flow and movement untraceability, suggests to recode messages based on a specified matrix. However, the advantage an attacker gains by knowing this encoding strategy and the routing mechanism is not discussed. Hence, although claimed otherwise packet flows and movement of users might be traceable when the Untraceable Linear Network Coding Scheme is used. In this paper, we investigate this open point and introduce an attack based on the knowledge of the coding scheme and routing. We show the success of our polynomial time attack in a simulation: For most realistic parameters the attacker can trace flows in the network to the receiver's mesh node with a success rate of 80% or more. Additionally, we discuss countermeasures to reinforce the protection of the network coding scheme.