Anonymous Communication in Ubiquitous Computing Environments

Abstract

Wireless networks such as WLANs which have already been commonplace will play an important role in providing the last mile access for ubiquitous computing environments. However, the wireless access technologies are accompanied with some security vulnerabilities that stem from the broadcasting medium. Although most of the vulnerabilities can be solved by the existing security countermeasures, there still exists the vulnerability of a message header. In most wireless access networks, the header part of each message, including the source and destination addresses, is transmitted in a plain-text format. This can be a security hole with adversaries collecting the revealed header information for a traffic analysis attack that can breach the privacy of the transmitter and receiver. In this paper, we focus on describing a solution to this problem, namely, the undesirable loss of privacy. Our main idea is to integrate address information with a conventional Message Authentication Code (MAC) and to replace both fields of the address and the MAC by an integrated code called the Address-embedded MAC (AMAC). Through detailed performance and security analysis of our scheme, we show that our AMAC scheme can guarantee privacy of a network while providing a provable security level with less overhead.