True anonymity without mixes

Abstract

Anonymity is an essential part of social structures. In the non-electronic world there are several services that are based on anonymous interactions between individuals. The migration of these services to the Internet world is infeasible without the provision of anonymizers to guarantee anonymity. Anonymizers based on mix computers interposed between the sender and the receiver of an e-mail message have been used in the Internet for several years by senders of e-mail messages who do not wish to disclose their identity. Unfortunately, the degree of anonymity provided by this paradigm is limited and fragile. First, the messages sent are not truly anonymous but pseudo-anonymous since one of the mixes, at least, always knows the sender's identity. Secondly, the strength of the system to protect the sender's identity depends on the ability and willingness of the mixes to keep the secret. If the mixes fail, the sender's anonymity is compromised. The authors propose a novel approach for sending truly anonymous messages over the Internet where the anonymous message is sent from a PDA which uses dynamically assigned temporary, non-personal, random IP and MAC addresses. Anonymous e-cash is used to pay for the service.