Securing pseudo identities in an anonymous peer-to-peer file-sharing network

MUTE is an anonymous peer-to-peer network that is used by hundreds of thousands of people to share files. Peers in this network are identified by randomly chosen pseudo identities and a probabilistic time-to-live counter is used to stop an attacker from being able to tell how far a search has come or has to go. The aim of the system is to hide the IP addresses of the file-sharers from an attacker that is acting as one or more peers inside the network. This paper describes the MUTE system, and then goes on to outline an attack on the anonymity of a peer based on “stealing” pseudo identities. We then show how using an authentication key as a pseudo identity can stop this attack and we describe the implementation of this solution as part of the MUTE system.