Shared Crowds: A Token-Ring Approach to Hide the Receiver

Because of the intensive usage of the internet and services provided over the world wide web, the privacy of the users is threatened by various attacks. This paper shows how to build a protocol for anonymous data transmission, with the primary focus on hiding the identity of the receiver (receiver anonymity), using multi path transmission and secret sharing. This protocol extends the crowds system by Reiter and Rubin, which only weakly hides the identity of the receiver. Due to the use of a circular channel topology the receiver is hidden even if timing attacks are mounted. Additionally this protocol gives the participating nodes the possibility to detect active attacks during the channel setup phase. Another positive aspect is the ability to handle some kind of node failures by repairing the virtual channel.