Geographical Ad Hoc Routing With Anonymous Properties

58 Pages·2015·0.36 MB·English

by  Tina Suen

Florida State University Libraries
Electronic Theses, Treatises and Dissertations The Graduate School
2007
Geographic Ad Hoc Routing with
Anonymous Properties
Tina Suen
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THE FLORIDA STATE UNIVERSITY

COLLEGE OF ARTS & SCIENCES

GEOGRAPHIC AD HOC ROUTING WITH

ANONYMOUS PROPERTIES

By

TINA SUEN

A Thesis submitted to the
Department of Computer Science
in partial fulfillment of the
requirements for the degree of
Master of Science

Degree Awarded:
Spring Semester, 2007
The members of the Committee approve the thesis of Tina Suen defended on April 6,
2007.

______________________________
Alec Yasinsac
Professor Directing Thesis

__________________________________
Mike Burmester
Committee Member

______________________________
Breno de Medeiros
Committee Member

The Office of Graduate Studies has verified and approved the above named committee
members.

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ACKNOWLEDGEMENTS

This work is made possible by the Department of Defense Information Assurance Scholarship. I
owe gratitude to my major professor Dr. Alec Yasinsac, as well as my committee members Mike
Burmester and Breno de Medeiros. I also want to thank my research group peers and friends.
Last, I am grateful toward my family for all their love and support.

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TABLE OF CONTENTS

LIST OF TABLES ..................................................................................................................... v

LIST OF FIGURES .................................................................................................................... vi

ABSTRACT ............................................................................................................................... vii

1. INTRODUCTION ................................................................................................................. 1

Ad Hoc Networks ........................................................................................................... 1
Security in Ad Hoc Networks ........................................................................................ 1

2. SECURE AD HOC ROUTING ............................................................................................ 2

Routing in Ad Hoc Networks ......................................................................................... 2
Secure Routing Theory ................................................................................................... 2
Secure Routing Protocols ............................................................................................... 7

3. SECURE GEOGRAPHIC AD HOC ROUTING .................................................................. 8

Geographic Routing in Ad Hoc Networks ..................................................................... 8
Secure Geographic Routing ............................................................................................ 10

4. GEOGRAPHIC ROUTING WITH ANONYMOUS PROPERTIES.................................... 11

GARAP .......................................................................................................................... 11
The Shape Function ........................................................................................................ 12
Routing in GARAP ........................................................................................................ 23
Optimizations ................................................................................................................. 24
Security Analysis of GARAP ......................................................................................... 24

5. CONCLUSION ..................................................................................................................... 29

APPENDICES

A. KEY MANAGEMENT PROTOCOLS .................................................................... 30
B. SECURE ROUTING PROTOCOLS ........................................................................ 39

REFERENCES ........................................................................................................................... 38

BIOGRAPHICAL SKETCH ...................................................................................................... 44

iv
LIST OF TABLES

1. Attacks on routing protocols .............................................................................................. 5
2. Routing protocols versus attacks ......................................................................................... 43

v
LIST OF FIGURES

1. Levels of Security ............................................................................................................... 3
2. Secure Route Discovery ..................................................................................................... 4
3. Security versus Reliability .................................................................................................. 7
4. Defining an Ellipse ............................................................................................................. 13
5. Distance to an Ellipse ......................................................................................................... 14
6. Shape Function Scheme #1 ................................................................................................ 15
7. Pinpointing center C ........................................................................................................... 16
8. Function determine_SC_DC() ............................................................................................ 20
9. Shape Function Scheme #2 ................................................................................................ 20
10. Shape Function Scheme #3 ................................................................................................ 22
11. Example 1 ........................................................................................................................... 26
12. Example 2 ........................................................................................................................... 27
13. Example 3 ........................................................................................................................... 28

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ABSTRACT

Mobile ad hoc networks, or MANETs, are wireless networks that do not depend on a
fixed infrastructure. The wide array of uses for ad hoc networks creates many different levels of
security requirements. This work begins by exploring various aspects of routing in ad hoc
networks and presenting some theoretical reasoning about secure routing. These thoughts then
lead to examination of secure geographical ad hoc routing, finishing with a new geographical
routing scheme GARAP, which holds anonymous properties.

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CHAPTER 1

INTRODUCTION

1.1. Ad Hoc Networks

Mobile ad hoc networks, or MANETs, are wireless networks that do not depend on a fixed
infrastructure. Mobile nodes may form networks on the fly for a variety of environments
including emergency rescue missions, sensor networks, military applications, and open networks
of personal wireless devices. Since these nodes are mobile, the ad hoc network can be
challenged with frequent topology changes as well as physical threats.
Wireless nodes can communicate directly with neighboring nodes that are within their
transmission ranges. To reach nodes outside of direct transmission range, nodes depend on each
other to forward their packets, creating a multihop network with many vulnerability points.
Therefore, one can see from this interdependence the importance of having secure routing
protocols to ensure confidentiality, integrity, availability, and non-repudiation.

1.2. Security in Ad Hoc Networks

The wide array of uses for ad hoc networks creates many different levels of security
requirements. For example, while the military network might be concerned about sensitive
intelligence, the sensor network may be concerned with disclosure of proprietary data and the
open network may be concerned about leaking personal information. Different security
mechanisms are used to achieve these security requirements.
Securing MANETs has many additional challenges than compared with fixed wired
networks. For example, security policies for ad hoc networks must more heavily consider the
protection needed against mobile wireless nodes being compromised physically. Ad hoc
networks can also be highly dynamic since wireless nodes are free to move around, making
topology control a challenging task. Furthermore, wireless nodes often have limited
computational power, battery life, bandwidth, memory, and other resources to confront these
challenges.
In [1][2][3], guidelines are given for securing ad hoc networks. Security concerns
encompass both physical entity security and data security, which includes authentication,
integrity, confidentiality, and non-repudiation. Availability is another significant concern since
nodes may leave the network or become unresponsive, disrupting communications or network
services. A robust network should take advantage of natural redundancy and maintain
connectivity. Access control must also be addressed to prevent unauthorized access.

The rest of this paper is organized in the following manner: Chapter 2 discusses various
aspects of routing in ad hoc networks and presents some theoretical reasoning about secure
routing. Chapter 3 discusses secure geographical ad hoc routing, while Chapter 4 introduces a
new geographical routing scheme with anonymous properties. Last, conclusions are given in
Chapter 5.

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CHAPTER 2

SECURE AD HOC ROUTING

2.1. Routing in Ad Hoc Networks

Routing can be considered to have two phases: a route discovery phase and a data
communication phase. In the route discovery phase, path(s) are sought from the source node to
the destination node. In the data communication phase, the path(s) are then used for actual data
packet transmission.
There are several approaches to routing in ad hoc networks. One categorization is table-
driven versus source-initiated on-demand [4,5]. With table-driven routing protocols, the route
discovery phase is implemented by having each node in the network being responsible for
maintaining routing table(s) and sending updates when routes change status. Routes are ready to
use when a node wants to enter the data communication stage; however, all routes are ready for
use regardless of whether the source needs them. With source-initiated on-demand routing
protocols, route discovery to a destination is initiated only when the source node wants to
communicate with that particular destination. Thus, routes are not immediately available (unless
a route had been previously found and stored) but are found only when needed. Both approaches
have advantages and disadvantages. The table-driven approach is proactive while the on-
demand approach is reactive. In general, table-driven routing protocols are more suitable for ad
hoc networks with heavier communication traffic since routes are constantly requested and the
route discovery traffic has less change of being extraneous. On-demand routing protocols would
then be more suitable for ad hoc networks with sparser traffic. In terms of higher mobility, on-
demand protocols are probably better for the same reasons as for heavier traffic.
An alternative categorization of routing protocols is network-centric versus source-centric
[6]. Network-centric routing protocols rely more on the network to construct routes.
Intermediate nodes make decisions on the path returned to the source. Source-centric routing
protocols depend more on the source itself. For example, the source node can collect distance
metrics to build the network view and then make the decisions on which routes to use.
Routing protocols can also be divided into distance vector or link state routing protocols.
These two routing techniques use different approaches to choose and maintain paths. Distance
vector routing protocols use a distance metric (such as hop count) to decide on which path to use
for each destination. A direction (next hop neighbor) is also stored. All nodes will routinely
send routing table updates at predefined intervals. Link state routing protocols base path
selection on a cost metric that is calculated from link characteristics (such as link status and
medium). Link state updates are sent only when link statuses change. In comparison, link state
often converges faster but distance vector is often simpler to implement. Hybrid versions of
these protocols may also be used.

2.2. Secure Routing Theory

The goal of a complete routing protocol is not only to provide efficient communication but
also provide secure communication. What is a routing protocol and what is meant when a
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