Heartbeat traffic to counter (n-1) attacks
George Danezis, Len Sassaman · 2003
A dummy traffic strategy is described that can be implemented by mix nodes in an anonymous communication network to detect and counter active (n - 1) attacks and their variants. Heartbeat messages are sent anonymously from the mix node back to itself in order to establish its state of connectivity with the rest of the network. In case the mix is under attack, the flow of heartbeat messages is interrupted and the mix takes measures to preserve the quality of the anonymity it provides by introducing decoy messages.