Privacy addressing and autoconfiguration for mobile ad hoc networks

Abstract

Allowing truly spontaneous and infrastructureless networking, mobile ad hoc networks (MANETs) are the future of wireless networks. However, most autoconfiguration proposals for MANETs lack privacy support, namely anonymity or pseudonymity and unlinkability aspects, which has become important considerations in many practical applications. This paper presents a novel privacy extension approach (PEA) for MANETs, which prevents eavesdroppers from identifying a particular mobile node by its address. In addition to privacy concerns, our scheme also brings some performance benefits, e.g., reducing the possibility of address conflict when the merging of separately configured networks occurs.

Introduction

As an important part of future communication, mobile ad hoc networks (MANETs) have attracted more and more attention from industry, government and academic organizations [1] and privacy issues have become important considerations. Any information of legal network users to which a malicious eavesdropper has access might be used to harm privacy. In MANETs, most protocols, including address autoconfiguration protocols [2], [3] and routing protocols [4], [5], presume that each node obtains an IP address and holds it until the node leaves the network due to the battery expiration or other unexpected reasons. Since every address remains constant over time, a malicious observer can correlate seemingly unrelated activity as being from the same node by using this address. Such information can in some cases be used to infer things, such as what hours an employee was active, when someone is at home, etc. which result in privacy harms.

Partial privacy is achieved in IPv6 by using RFC 3041 [6], which generates addresses from the interface identifiers that change over time. This makes it more difficult for eavesdroppers and other information collectors to identify the same node in different transactions when different addresses are used. However, many autoconfiguration protocols for MANETs do not generate addresses from interface identifiers so RFC 3041 cannot be helpful. Especially, in autoconfiguration protocols following stateful approaches [2], addresses are managed by allocation tables and a node cannot freely generate an address by itself, so directly changing interface identifiers cannot be feasible.

In order to overcome these problems, this paper proposes a novel privacy extension approach (PEA) to autoconfiguration protocols for MANETs that can lessen those privacy concerns in environments where such concerns are significant. PEA divides the previous autoconfiguration protocols into three categories by the methods of generating addresses and defines the way of generating privacy addresses for them accordingly. By using privacy addresses, we believe that the proposed scheme has created the necessary conditions for the design of other protocols, such as routing protocols with privacy support.

Our main contributions include:

• An overview on privacy support of existing autoconfiguration protocols for MANETs.

• The novel privacy extension approach (PEA) to existing autoconfiguration protocols for MANETs.

• The demonstration of the performance benefits of PEA, e.g., reducing the possibility of address conflict when the merging of separately configured networks occurs.

• We point out that it remains an open research topic that the address evenness can be used to reduce the number of addresses required to change in MANETs.

The rest of the paper is organized as follows. Next section gives an overview of issues and current related efforts, including privacy addressing and autoconfiguration protocols. Section 3 presents the main idea of privacy addressing in MANETs and explains the detailed methods of generating privacy addresses. Furthermore, the influence of our scheme on existing autoconfiguration protocols is discussed in Section 4, and the benefits of our scheme are emphasized. Finally, Section 5 concludes this paper.